Apple iMac G5 Motherboards DIY Repairs How to Fix Bad Caps Guide

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Purchase high quality, low ESR, motherboard grade, long life, high temperature rated capacitors for your iMac G5 motherboards and PSUs.

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iMac G5 Take Apart Procedure
Help please, my beautiful Apple iMac G5 Computer is broken.

The first in a series of how to fix an iMac G5 PowerPC mother board (MOB).

This procedure is for repairing the iMac G5 MOB Logic Board and video problems. For Apple iMac G5 PSU, see how to fix an iMac G5 power supply.

Click here for Apple iSight G5 logic board model information.

The success rate for these do-it-yourself repairs are quite high, at greater than 95% when following the instructions. *** See note at the end of the article.

Hello to the French MacGeneration.
Bonjour à la France MacGeneration.

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I had to get the lead out when it comes to repairing the Apple iMac G5 PPC motherboard problems. Beware; please read these MOB iMac G5 repair instructions carefully before attempting this procedure for replacing of the capacitors on an iMac yourself. This Apple iMac G5 logic board repair is not as difficult as it sounds. If you wish to save a substantial amount of money on iMac repairs and mother board replacement, possibly have a buddy that can help, or even have some experience yourself with a few handy tools at your disposal, or have a local computer repair technician that might be willing to do the job, or willing to take on a challenge yourself and have a dead mac you wish to revive, then this is the best Apple iMac G5 repair procedure for you. Also, beware of the time commitment involved with this Apple computer repair. “Be prepared,” is the old Boy Scout motto, and that is no lie when it comes to tackling this Apple product repair yourself. iMac serial numbers are listed below to see if your Apple serial number was covered in the original problem.

Additionally you may also go to any Apple Retail Store with a Genus Bar, and have the Apple folks take a look inside the G5 and look at the caps on the iMac logic board for you. Find the nearest Apple Retail Store – Genius Bar in your area, and take your Mac and get in the queue, or better yet, make an appointment online for the Genius Bar. Apple provides technical support for Mac, iPod, Apple TV, and iPhones at the Genius Bar too.

Apple iMac G5 Hard Drive Data Recovery for those that want to recover the information from their hard drives on a dead Mac.

Apple iMac G5 PowerPC Motherboard Repairs Picture Before

Apple iMac G5 Motherboard Capacitors Problem
1st Generation Apple iMac With Bad Caps

This is a close up view of the Apple iMac G5 Motherboard (20 inch model) with the bulging, leaking, and exploding capacitors problem. Take a look at Fat Caps & Ripple Current for more info into engineering and design of electronics equipment. This is a first generation model pictured above. Go to the bottom for second generation iMac G5 comparison picture. This Apple G5 PPC motherboard is three years and two months old. The symptoms of the problem were: video shaking, video disappearing, video lockup, system lockup, intermittently could not power down, intermittently powering up problems, and strange program lockups. Here is a YouTube Video from someone else that shows a very similar Apple iMac G5 startup problem with the video display. Note the vertical lines in the video display.

After Apple iMac G5 Motherboard Repairs Picture

Apple iMac G5 Capacitors
Location of Capacitors on MOB Next to Power Supply on 1st Generation Apple iMac G5

Article updated 12/17/11: Very Important! High Quality Low ESR capacitors, computer motherboard grade, 105ºC, 10mm X 16mm, caps are available for sale in kit form.

The logic board capacitor sizes included in the kits, are the original sizes of the capacitors on the logic board; making your job much easier to replace them. Important Note: The caps are a perfect fit for both diameter and height requirements, which is very important for the caps’ clearances to the back cover and extremely close mounting requirements. Reference the article: Fat Caps & Ripple Current for more electronics engineering & design insights.

International shipping is available for most countries worldwide. If your country isn’t listed for a shipping destination, please let me know to add your country to the list. Please provide your full name (first and last name) when ordering capacitors. Please refer to the Shipping Page for ordering and shipping information.

Send me an email if you would like to purchase ten or more iMac G5 cap kits, along with a note of which of the different cap kit sets you are interested in. Note: Apple early and late model iMac G5s with the PowerPC processor have different quantities of caps required on the MOB. Capacitor information is provided at my secure eCommerce website. Visually verify what capacitors your Apple iMac requires based on the pictures, and bring your iMac G5 back to life today.

Send me an email with any questions, or other special order requests. I have the power supply cap kits available too. Compare your PSU to the pictures. Feel free to contact me any time, with any questions. Take a look at the PSU cap kits that are available for purchase.

Apple iMac G5 Motherboard PowerPC capacitors replaced. The iMac mother board pictured above shows the locations of the new capacitors installed. Note: The heights and diameters of the new capacitors are slightly bigger in this picture, than the original caps. Upgraded to 1,800 uf 10 volts from the original 1,800 uf 6.3 volts. Please note these were larger diameters and taller than the original ones. They were a very tight squeeze between each of the caps. Back cover still clears (barely clears) all components. This information is for documentation sake. I don’t really recommend going up in the heights and diameters here. That is why I am selling the proper size caps for the mother board. If higher voltage caps, with the correct capacitance, good maximum current ratings, low ESR ratings, and temperature ratings were available, in the same exact physical case sizes, it would be OK to install those. However, higher voltage caps are not available in this size packaging.

Important notes are as follows. It appears as though lead free solder was used and a polymer was coated on the assembled motherboard on the bottom. A very hot soldering iron is required. Doing it yourself is not for the faint at heart. But fear not, you can do it if you follow this procedure.

It’s pretty easy to open the iMac case (first and second generation iMac models) and visually look at the caps. Simply lay it face down on a soft cloth. Loosen completely, the three screws on the bottom edge (Note: the screws will stay in), then just lift the back cover off from the bottom up. Visually inspect the capacitors for signs of expansion or tops that are rounded even slightly are an indication of bad caps.

Once you determine the status of the caps, then everything has to be disassembled, beginning with the removal of the power supply, which also can be a victim of bad caps and/or poor engineering, (see: DIY G5 power supply repair) in order to get to the bottom of the motherboard. Refer to the various Apple iMac G5 user and do-it-yourself part replacement manuals for details and visual instructions on how to remove various items. The cover is easy to take off by simply turning the three screws completely counter clockwise on the bottom of the computer’s lower edge and then lifting up the rear cover. The power supply (see: Apple Power Supply Removal and Replacement Instructions) then can be removed by unscrewing the mounting screws and disconnecting the main plug and the ambient light sensor cable (if you have an ambient light sensor model) to the motherboard, and partially turn the middle screw (about 5 turns clockwise) on the bottom of the case, which releases the back cover clamp, and the PSU will then lift out. Be careful not to damage the automatic ambient light sensor mounted on the bottom edge of the power supply unit. See this YouTube Video for what is inside the iMac G5 Computer. However once the cover is removed, the rest of the computer disassembly is quite a delicate task for most non technical people and requires special tools. Apple never actually intended for the end user to remove everything that I removed in order to get to the root of the matter.

A Torx screwdriver is not necessarily needed, though it would be helpful to use one. Check out the very handy magic screwdriver with the telescopic shaft with various size TORX bits for the mother board and other items. I had some precision screwdrivers that fit somewhat precisely in the fasteners, but it certainly would have been easier if I had the Torx screwdriver to begin with.

Here are some additional service notes and soldering tips. In addition to requiring a super hot soldering iron, one with good heat transfer and quick heat recovery, (a 60 watt soldering iron minimum is recommended) you may also need to grind off some of the polymer resin that is on the bottom of the circuit board, covering the capacitors’ leads, in order to get access to the lead free solder in the first place. See Soldering Tips for Lead-Free Soldering for detailed soldering tips and information. A proper soldering iron will make your job much easier and be able to quickly remove the capacitors from their mounts without having to do any special resin removal. I suggest ordering wider soldering tips, for use with a good quality soldering iron for a hotter and faster concentration of heat transfer. Soldering TipsIf you don’t use a hot enough soldering iron, the solder will never melt; you will just barely heat up the circuit board, and the capacitors will not come out. Also, if you have to
o small a tip, the heat will not transfer to the mother board very well, and the tip will cool down too fast when trying to melt the lead-free solder. If anyone would like to make a suggestion for a good quality soldering iron, at a reasonable price, with quick heat recovery, that can melt the lead free solder on this Apple motherboard, let us know here.

CHIPQUIK at JWestSales.comWhile removing the 20 capacitors on the G5 logic board, I experienced broken leads from capacitors that were falling apart, and leads that pulled out of the capacitors themselves, because of the extra heat that is required to melt the lead free solder in the first place. Note the following section is included for information purposes only. Some folks have recommended I remove this reference to drilling the circuit board holes out. While this is not a recommendation of circuit board drilling, I have included it here only as to what I had to do to fix the problem. Others may have a much better “hole” cleaning solution. In fact, I highly recommend reading about the “pin point tip” desoldering trick, the new Chip Quik desoldering alloy and flux, and the importance of using a proper soldering iron first. To begin with, I had to use a Dremel power tool in various ways, though with a hotter and greater wattage soldering iron designed for lead-free soldering, which I bought for future MOB repairs, the following would have been a non issue. Prior to removal of the G5 caps, it was first necessary to grind off the polymer resin and some of the excessive lead lengths from the old capacitors with a small grinder tool attached to the Dremel, and then drilling out some circuit board holes with a number 72 (0.0250 inch) solid carbide drill was what I did when the old cap leads broke off in the holes of the printed circuit board. Beware of, drilling the holes out could damage the circuit board and break carbide bits inside the holes. That would not be good and making it most difficult to fix. Suggest using the Chip Quik desoldering product here instead of drilling out the pads on the PCB. Also note that drilling the holes can damage the through platting which is designed for connecting the top and bottom hole surfaces of the PCB, and might also be used for connecting to other traces and layers of the multilayer PC board. This would also make for a really bad through solder hole connection on the new capacitors being installed.

When replacing the capacitors it is important to note which are the positive and which are the negative leads when installing in the board. New capacitors generally have a long and short lead (short lead is usually the negative lead) along with a negative indicator written on the side of the cap itself. Warning: Do not install capacitors in backwards, or you will blow up the new caps and possibly damage the circuit board. The circuit board has the positive hole marked on the printed circuit board itself. Here is a how-to demonstration of how to replace capacitors. Also, keep in mind when soldering your new capacitors to the motherboard, if you just have a round blob of solder on the bottom of the board, without it fully flowing through the holes, you can have cold solder joints. If you place heat on the legs of the caps for too long, you can also damage the new capacitors. A very hot soldering iron with quick heat recovery, and a wide tip is the best solution. See notes above about the recommended soldering iron. More information at: Soldering Tips For Lead-Free Soldering.

Special Attention to Details Area. At this point in the iMac repair process, after the new caps are completely installed, and properly soldered in the holes on the motherboard, you must trim off the excess new caps’ lead lengths on the bottom surface of the motherboard. Take a pair of diagonal cutters, and snip the leads to the proper lengths, making sure you do not get any metal fragments lodged in the motherboard or inside the chassis area of the iMac computer. Failure to cut the leads to the proper lengths could result in short-circuits, damaged capacitors, blown electronic components, and a blown iMac motherboard or power supply unit.

iMac Logic Card Bottom Side View

Once the capacitors are replaced on top of the motherboard, then it is time to reinstall the motherboard back into the chassis. Pictured above is the bottom of the MOB logic card, with the small square just to the right of the “.com” which is the location of the main processor (CPU) that protrudes from the bottom of the logic card. Do not try to remove this processor chip. Clean this area and the metal heatsink area that matches up to the CPU with alcohol, and apply fresh heat sink compound. I suggest when ordering the capacitors that you also order the thermal paste heatsink compound at the same time. You can order the thermal compound online from my J West Sales Store.

From George T.

“First off, the cap replacement fixed all the prior problems: i) endless blue screen on normal boot but OK with safe boot; ii) video breakup and horizontal bars; and iii) excessive fan speed. Now to the issue at hand…

The first thing the CPU does, based on ROM instructions, is check the RAM. If the RAM is OK the chime sounds. Therefore, if there is no chime, either the CPU is not working properly or a RAM chip is defective. This test covers the basic hardware and comes before the hard drive boot starts. The 3rd LED comes on early in the hard drive boot, but definitely after the chime.

My problem was no chime, and the reason was that the CPU wasn’t working. The CPU wasn’t working because I slopped some thermal grease over the circuit board items above the CPU. These items are marked “RAM clock” on the board.

Internet research revealed that the thermal grease is full of metallic silver. Furthermore, although there is little or no electrical conductivity, the grease is very capacitive. If it is sitting on the components, or even above the insulating copper tracings of the circuit board, it has low impedance at the clock frequency — it is a virtual short circuit. Once I cleaned off the grease, the board worked properly.

I would suggest that you incorporate this caution in your otherwise excellent instructions.”

Jim W. “Thank you George for the great insight.”

Arctic Silver Inc. manufactures a very good quality thermally conductive grease for modern high-power CPUs for Apple, Intel, and AMD, along with other high-performance heatsinks or water-cooling applications. Arctic Silver manufactures the Arctic Silver 5 product and the Arctic Silver Ceramique thermal compounds, and are world renown as being two of the best thermal heatsink compound options available. CPU Overclockers rave over Arctic Silver products.

When applying the Arctic Silver thermal paste compound (either the Arctic Silver 5 or Céramique 2), less is better, (see the warning on the left) paper thin is best. Please review instruction sheets for applying Arctic Silver 5 and also the Arctic Silver Céramique 2 instructions of use and proper application procedures. On Motorola chips, I use the covering of the whole surface with a very thin layer method as opposed to a dot in the middle method. Just be sure that very little if any comes out of the edge of the chip when the board would make contact with the heat sink. The way the application works is, the thermal paste fills the minor imperfections in the metal surfaces and removes the air spaces between the two joining metal surfaces and helps improve the heat transfer between the CPU and the heatsink. See image above for the the small square area right location, for the thin application of the thermal grease. Check out this Thermal Paste Comparison from Techware Labs review of the pros and cons of using the most popular thermal pastes available at the time the article was written. The article, while being somewhat dated, provides good insights into the differences between Silver Grease and Silicone Paste, and which is better for a computer CPU heatsink application. I would stay away from the silicon paste compound, because quite frankly, silicon paste or silicon grease does a poor job of keeping the CPU cool under load conditions based on the test results at that time.

Believe it or not, I have to say the finished project has worked like a champ. As a matter of fact, I have used the same iMac G5 here to do the pictures with a program called Skitch, and posting this article using Firefox running on the iMac too.

At this point in time, I’m not sure I would use any of those Rubycon Caps again. As the old saying goes, “Fool me once, shame on you; fool me twice, shame on me.” Rubycon, why did you use an improper electrolytic recipe? Was it cheaper to make those caps with the cheap electrolyte with the missing ingredient?

Rubycon MCZ Capacitors Bad CapsNote: I inspected my work a couple of weeks later, and decided to replace the five other capacitors also. I found some evidence online that these other capacitors go bad too. The 20 capacitors that I first replaced all looked good. Upgraded these five additional caps from the original factory installed 1,000 ufd, 16 vdc caps, to 1,000 ufd, 25 volts DC, operating temperature range: -55º to 105ºC. I should point out here that these were a larger diameter and taller than the original ones. They were a tight squeeze. I picked up both sets of capacitors at Halted Electronics a surplus store in Santa Clara, CA. They also have some new electronic components available at the store too. Generally speaking, it is usually OK, and advisable, to increase the DC voltage rating of the capacitors while maintaining the same MFD, microfarad rating. Don’t cut corners. As a suggestion, if you see any of the capacitors that have problems, it is highly advisable to replace the entire group of caps at the same time. If one or two of the caps are in the failure mode now, they would more than likely all be destined to fail in a very short time.

As an aside note, I included the previous paragraph information in this article as a historical troubleshooting and engineering evaluation note. I would suggest not installing surplus caps as a general fix for this problem and subsequently have installed “new” caps in this iMac. The problem with “old” surplus caps, you have no idea how old and long the capacitors have been sitting on the shelf with potential “shelf life rot”. I actually witnessed this capacitor shelf life rot on some of the first capacitors I looked at in the surplus bins before they got more from the back room. Many of the surplus caps are generic brands, or do not have proper low ESR ratings, or are general purpose capacitors that should not be used in mother board applications. Note that as of 8/15/2010, as I mention above, I upgraded this originally repaired iMac G5 with the surplus “old” caps to the proper sized and proper voltage rated “new” capacitors. Don’t shortchange yourself in your repair efforts here; order proper low ESR motherboard and power supply grade capacitors.

LED Indicator Lights

iMac G5 LED Indicator Lights

The LEDs on the main logic board (motherboard or MOB) indicate the following:
* LED #1 means it is detecting trickle voltage from the power supply unit, PSU. If you don’t see this LED, with the machine off but plugged in, it is not a good candidate for PSU repairs unless fuse is blown on the PSU itself, and the PSU should be replaced in this case.
* LED #2 comes on when the MOB sees all the correct powers (proper voltages present from PSU).
* LED #3 indicates the computer and LCD are talking (communicating) OK.
* LED #4 is strictly an overheating indicator LED, and should not go on under normal circumstances.

Another interesting bit of information regarding noisy iMac G5 fans and internal temperatures that I discovered after the G5 motherboard repair, it became apparent, the computer fans were running a lot quieter. No more Hoover Vacuum cleaner sounds. Also, the overall temperature of the computer is operating at lower temperatures in my opinion. I found this free Temperature Monitor program for keeping track both instantaneously and in a graph chart form, of what the CPU, Hard Drive, and Smart Disk drive temperatures are operating at. I did not have the program installed prior to the problem, but after I repaired the printed circuit board, I installed the temperature recorder and discovered that the CPU temperature does not get much above 65 degrees C, even with a warm ambient room temperature. The average temperature of the CPU is somewhere in the 58 degree C range (136 degrees Fahrenheit). Note: I keep my computer running for days and weeks on end.

I am still a bit ticked off that I had to go and do this myself. I had the Apple extended care warranty, but I missed out on the free repair by two months. If I had the problem occur two months earlier, Apple would have covered it free of charge. Apple never sent a message concerning the problem. It took some investigative work to find out that they had issues with the capacitors leaking, but they downplayed the severity of the problem.

This should not happen with a product three years old. In Apple’s defense I can tell you that I found evidence that many other computer manufacturers also had the capacitor problems from buying low cost capacitors from a stolen electrolytic capacitor recipe from Taiwan. See this video showing computer circuit boards with bulging, leaking, and exploded capacitors on board from a variety of computer manufacturers. While I am a fan of Apple products, I just have to say this is not one of their stellar computer products moments. I’m sure it was a business decision to not have a product recall, but I think they should have had one. Of course, I guess you could say, I’m a little biased on this issue.

Yes, the Apple Store folks were nice enough to take a look inside the iMac at the local Mac Genius Bar, and give me a heads up on what the problem was, though it only took a five second look inside for the Apple guy to tell me that I need a new motherboard, and oh by the way, the total cost (approximately $750.00) was going to be two thirds the cost of a brand new computer. The Apple Store guys suggested I buy a new Apple desktop computer, one that is faster and better.

I said, “not today.”

Inside 1st Generation Apple iMac G5 20 Computer

Inside Apple iMac G5
Location of Major Components in 1st Generation Early Model Apple iMac G5 20

Here’s what you get (pictured above) inside the Apple iMac G5 Desktop computer. CD/DVD in the upper left, two fans in the top center, hard drive top right, two memory slots available for up to 2 GB of two 1 GB DDR PC 3200 memory sticks, power supply in the lower section, and the mother board in the middle. Look closely, and you can see the on board battery for the motherboard.

Apple Second Generation iMac G5 Computer

Compare your Apple iMac with the picture above. Is yours an early model first generation or late model second generation Apple iMac G5?

Printout this PDF file of the Apple iMac G5 Motherboard Repair article for reference before you take a bite of your Apple apart. Opun the back door.

iMac G5 17 & 20 Inch Models

Here is a Apple link on how to identify your iMac and how to check the EMC number on the bottom label.

Contact Me

As one last thought before the night is over, lead free solder is a pain in the rear. Repairing all types of electronics is going to become increasingly difficult with these high temperatures required to remove and install new components in their place. We are becoming more and more, a disposable society.

Also, I think it is quite comical reading the Apple repair extension program especially the section about not fixing the desktop computer yourself, now that I have fixed it myself. And, the one that says if you don’t have any of these problems there is no need to do anything, “just wait for it to break after warranty,” my two cents added.

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Read it for yourself. I guess I am breaking all the rules here.

And for those that want to check out their iMac G5 for the extended service, here is the quoted information from Apple support.

iMac G5 Repair Extension Program for Video and Power Issues

November 2, 2006

Frequently Asked Questions

iMac G5 Repair Extension Program for Video and Power Issues
The iMac G5 Repair Extension Program for Video and Power Issues applies to first generation iMac G5 computers that have video or power-related issues as a result of a specific component failure. If your iMac G5 is exhibiting any of the symptoms listed below and your computer’s serial number is within the noted ranges, your computer may be eligible for repair, free of charge. If Apple or an Apple Authorized Service Provider (AASP) determines that your iMac G5 computer is eligible as part of the program, the repair will be covered by Apple for up to three years from the original date of purchase even if your iMac G5 is out of warranty.

This is a worldwide Apple program.
Affected systems will exhibit one of the following video- or power-related symptoms:

  • Scrambled or distorted video
  • No video
  • No power

Note: If your iMac G5 is not experiencing any of these symptoms, you do not have to contact Apple or any Apple Authorized Service Provider.

Which iMac G5 computers are affected by the iMac G5 Repair Extension Program for Video and Power Issues?

The program is available for certain first generation iMac G5 models that were sold between approximately September 2004 and June 2005 featuring 17- and 20-inch displays with 1.6GHz and 1.8GHz G5 processors.

The affected iMac G5 computers have serial numbers where the first 5 digits fall into the ranges noted below.

Serial Number ranges:

  • W8435xxxxxx – W8522xxxxxx
  • QP435xxxxxx – QP522xxxxxx
  • CK435xxxxxx – CK522xxxxxx
  • YD435xxxxxx – YD522xxxxxx

Some second generation iMac G5 computers have serial numbers that fall within the upper band of the ranges listed below. Only first generation iMac G5 computers are affected by this program.
Where do I find the serial number of my iMac G5?
The 11-digit serial number is located on a label under the foot of the iMac G5. There is a bar code underneath the serial number.
To view the label, hold the sides of the iMac and gently lay the computer face down on a soft, clean towel or cloth.

Is the iMac G5 Repair Extension program available for other Apple computers?

This program applies only to the systems noted in this FAQ. Other versions of the iMac G5 line are not part of this program. Click here for more information on how to identify iMac G5 models.

How can I tell if my computer is affected by the component failure identified for the iMac G5 Repair Extension Program?

An Apple technical support representative or an Apple Authorized Service Provider (AASP) will need to physically examine your computer to determine if the component failure identified for the iMac G5 Repair Extension Program affects your computer and, if so, arrange for the repair.

How can I participate in the iMac G5 Repair Extension Program?

To participate in the program, please bring your iMac G5 to the Mac Genius Bar at your local Apple Retail store or Apple Authorized Service Provider (AASP), or call your local Apple Contact Center.

Apple Retail Store

Apple Authorized Service Provider

Apple Support Contact information

What if my computer exhibits symptoms not caused by the component Apple has identified for the iMac G5 Repair Extension Program?

It is possible that your iMac G5 may exhibit video or power issues that are unrelated to the component failure identified by Apple as part of this program and are not covered under this program. Apple or an AASP can help you troubleshoot these issues. If your iMac G5 is not covered under warranty or an extended service agreement, such as the AppleCare Protection Plan, repairs for other issues will be made at your expense if you request that they be made.

I have a remanufactured iMac G5 that fits the description noted. How can I determine whether my iMac G5 qualifies for the program?
If your iMac G5 is one of the models listed and exhibits one or more of the symptoms above, please bring your iMac G5 to the Mac Genius Bar at your local Apple Retail store or Apple Authorized Service Provider (AASP), or call your local Apple Contact Center. An Apple technical support representative or an AASP will examine your computer to determine if the component failure identified for the iMac G5 Repair Extension Program affects your computer and, if so, arrange for the repair.

Is there a cost for participating in the iMac G5 Repair Extension Program for Video and Power Issues?

If Apple or an Apple Authorized Service Provider (AASP) determines that your iMac G5 computer is eligible as part of the program, the repair will be covered by Apple even if your iMac G5 is out of warranty. Customers are responsible for transportation costs to eligible ASPs/retail stores.

How long is the iMac G5 Repair Extension Program available?

The program covers affected iMac G5 computers for up to three years from the original date of purchase. Apple will continue to evaluate the repair data and will provide further repair extensions as needed.

Does the iMac G5 Repair Extension Program extend the warranty coverage on my iMac G5?
No. This program does not extend the standard warranty coverage.

Are there any known safety issues caused by this component failure?

Can I determine if my iMac G5 has the component failure and fix it myself?
No. Apple or an Apple Authorized Service Provider (AASP) must evaluate whether your iMac G5 computer is eligible as part of the program and then conduct the repair.

If my iMac G5 is still under warranty, how does this program affect me?
If your iMac G5 is eligible for the program and within its warranty period, you will have your system repaired at no cost to you. If your iMac G5 experiences the symptoms described above and is determined to be eligible under this program by Apple or an AASP after your Standard One Year Warranty expires, the program covers affected iMac G5 computers for up to three years from the original date of purchase.

Home >Support > iMac > iMac G5 Repair Extension Program for Video and Power Issues

*** Just as a reminder, it is also a good idea to check your iMac G5 power supply. A bad power supply, will produce excessive ripple on the output voltages because of bad internal PSU capacitors, and can cause your new capacitors on the MOB to quickly fail. It is not hard to check the PSU caps. Go to the article on the Apple iMac G5 Power Supply for more detailed information and what you should be aware of. I have the complete PSU cap kits in stock. For a list of the capacitors required on the PSU, take a look at the Inside the Apple iMac information articles.

A Few Concluding Remarks

  • Do a quick visual inspection of the inside of your iMac G5 for bad caps.
  • Replace both types of caps completely even if one or two is visually bad, since it is most likely the other caps are in a failure mode too.
  • A good soldering iron or station is most desirable for this DIY project. Use good lead-free soldering techniques.
  • Inspect your iMac G5 Power Supply too. Bad caps in the PSU can directly affect the caps on the MOB.
Note: If you have any questions or comments feel free to email me. I’m always ready to answer a question for you, and very much appreciate your comments and feedback. Thank you. Best regards, Jim


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Patrick C.


I’ve ordered many cap kits from you in the past 2 years and have repaired many iMacs, so thanks for all your good work here!

My latest repair, a 2GHz 20″ G5 iMac in which I replaced all the caps on the logic board AND on the PSU, is now working again with one exception.

It always boots fine, and runs well, but once or twice in a normal 8 hour work day it goes to sleep. Tapping the keys or wiggling the mouse always brings it back. And then it will work for hours just fine!

Sometimes it goes all day without dozing off, other days it sleeps once or twice a day.

Any ideas?


Patrick C.

Jim Warholic


I suspect this is probably due to a cold solder joint on one or more of the caps. Or, maybe the SMU needs to be reset. Search Google for SMU PRAM iMac G5 reset for information from the Apple website on the service procedure of how to do it. Note the following: “The SMU (System Management Unit) is a microcontroller chip on the logic board that controls all power functions for your computer.” I have posted the Apple link in other places, but thought it better to make it so anyone can find the info if Apple updates or changes the link.

Simon Hewitt

Removing Electrolytic Capacitors

1. Heat up one solder joint/lead while applying pressure to the top of the capacitor in the direction of the other lead. As the solder melts the lead will rise up a few mm.

2. Repeat procedure on the other joint/lead, pushing in the opposite direction. The second lead will rise up a few mm.

3. Repeat steps 1 and 2 until the capacitor is free.

4. Use solder braid to suck-up solder from the through-hole (working from each side).

NEVER DRILL PCB HOLES – There are multiple (inner) layers to a modern PCB and you can easily damage the connections throughout the length of the hole.

It is better to cut away the capacitor ‘can’ to just leave the leads protruding from the PCB and then de-solder these easily…


Jim Warholic

All good points Simon. However, believe it or not, there are times where even cutting away the capacitor “can” will still have major difficulties in getting the leads to come out of the tight holes. What happens is that the pad and thick circuit board act like a huge heatsink, sucking away the soldering iron heat, and sometimes making it practically impossible to remove the leads from the holes. This is especially true when it comes to the lead free solder that is being used on the boards today. Read my lead free soldering tips.

Yes, solder wick or solder braid will help, but still even with that, sometimes additional help is required for removal. For example, the Chip Quik product is very helpful in removing these capacitors.

Simon Hewitt

I’ve used it many times to remove caps (or any other two-legged component)on a system board with minimal dammage to the board or component.

You may need to apply more solder to the joint so the heat is transferred propperly and allow some more time – But it always works!!!

>> The main point is to heat one joint and then apply pressure to the capacitor so the lead rises out of the hole slightly. It will take a few goes on each side, but eventually it will come out…

If that fails cut the capacitor out…

Jim Warholic


To address your comment: “- But it always works!!!”

I have used all of your tips many times myself, and it has always worked in the past. However, I have reworked plenty of Apple boards to tell you that it does not always work in getting the legs of the capacitors out of the holes by cutting away the capacitor can, and then removing the legs themselves. Part of the problem is the engineering design of the board with the relatively tight hole diameters in relation to the size of the capacitor legs, the thickness of the circuit board, and the surface area of the solder joint on these Apple logic cards can all fight against easy removal with the steps you have outlined.

In effect, the legs of the capacitors become lodged in the holes, making them very difficult to remove through normal best soldering practices of the past.


Simon Hewitt

The secret of the ‘cutting away method’ is to leave enough of the capacitor left that you can grip with pliers and then extract from the top of the board!!!

Anyway, cutting away the cap was final comment I added as a ‘last resort’ method…

The ‘wiggling method’ will remove the capacitor intact, and then the pads just need a quick clean-up with solder wick – This method always works.

Jim Warholic

Simon, Simon,

I can assure you that no, it does not “always work.”

First off, some of the capacitors are so bad (bulging and heat damage) that the legs actually pull out of the capacitors very easily to begin with when heating up the legs. Additionally, if there is any leg sticking out of the hole, when you go and grab it with pliers, the pliers themselves act as a good heatsink for cooling off the entire leg lead when trying to heat it up with a soldering iron. Then, the lead will actually break off at the top of the hole, instead of the leg coming out of the hole.


Hello Jim

I have an imac G5 17 inch isight version (Nov 2005) and have the notorious vertical lines (over 30 of them) and also the white strip left of centre of the screen. Apple say that my machine is classed as ‘vintage’ so unable to help. Is there anything I can do to rid of this problem? Will a replacement LCD screen do the trick if I can get hold of one? Is it easy to replace myself? Everything else about the mac is absolutely fine.

Thanks very much


Jim Warholic

Hi Tony,

A couple of things that I would check right off the bat, are the capacitors on the logic board and inside the power supply unit. If any of those capacitors are bulging, then that is a possibility of the cause of your problem.

If the capacitors do not have bulging tops, that does not guarantee that they are good, but at least, if the caps are bulging, it is a visual indication that they are bad.

Another thing that you could try is plugging in an external monitor with an Apple mini VGA to VGA adapter. Refer to the link for hooking up an external monitor on an iMac G5, which by-the-way, is pretty cool to do if you have an extra external monitor around. This can actually extend your desktop.

If doing all of those things above, and the problem does not show up on the external monitor, then it is possible that the LCD screen is bad in the iMac, but by no means is that a 100% guarantee.

As far as how difficult it is to replace the LCD screen itself; I would refer to these Apple service manuals for more details on how to work on, disassemble, and replace various sub-assemblies for just about any Apple product.

One more thing, is many of these iSight models have had problems with the BGA – Ball Grid Array, that is used on the main graphics chip to attach it to the board. Due to excessive heat buildup inside the G5 iSight model, which sometimes results in cold solder joints occurring between the main chip and the BGA. In this case, some folks have tried repairing those type of issues with a process called reballing BGA with varying degrees of success.

Hope that helps you,


Bill Maslin

Just a few comments and a warning regarding recapping a 17″ G5 1.9 Mhz iSight iMac. Well, first let me say that the recapping was a total failure. On restart, the iMac did exactly the same things that it did when it failed, ie, normal gray startup screen, then weird screen artifacts, then black screen or peculiar tints (eg, pink on the left edge) then the fan taking off. By the way, none of the caps on the logic board were bulged. And for reference, for a nonprofessional, I have a fair amount of experience working with solder (been in ham radio since 1962!).

I just did a Google search and found that the iSight iMac logic boards are very different than the previous generation G5 iMacs. In addition to the possibility of capacitor problems, graphics failures are attributed to failure of the 512 MB onboard RAM (only the iSIght iMacs have onboard RAM) or to deteriorating solder joints on the GPU. There is apparently no way to fix the RAM, but the GPU can be “re-balled.” However, I’ve put enough money into this project so I’m going to pull the drives and trash the rest or perhaps sell some of the parts on eBay. Or maybe I should put the logic board in the oven at 385 degrees and see if the graphics chip reattaches! I wonder what that temperature would do the the plastic sockets on the board? Or maybe try a heat gun on the GPU?

Anyway, as I implied above, I put a lot of money and time into this repair. Jim’s instructions were great as was ordering the caps, solder, etc from JWest sales. No complaints there. And he wasn’t kidding about the challenges of dealing with lead-free solder on that super heavy iMac circuit board. It was absolutely amazing how that board would sink the heat away from the connection.

I’d always wanted a decent soldering station so I bit the bullet and bought an Aoyue 2900 unit. It included a pointed tip that I knew was worthless for the iMac board so, on the vendor’s recommendation, I also ordered a 1.2 mm bevel tip. It was also inadequate so I had to order another tip, this time a 5.2 mm bevel tip (for another $14) and it worked well to unsolder and solder the caps.

The needle (held in small “vise-grip” pliers) combined with heating from the pad side worked well to open the holes. If I had it to do over again, I would have spent less time trying to get every bit of old solder off the pads. I think that as long as you have most of it gone, you’re probably OK.

Regarding getting the iSight logic board out: On page 69 the Apple service guide says to disconnect seven connectors from the board. However, just do the first six. There just isn’t room to pull the camera board connector loose (the big circle at the extreme right on on p. 69). Instead, wait until you’ve removed the logic board screws so that you can move the logic board sideways and get enough clearance to grab those tiny wires. And when you’re reconnecting the logic board, make sure you pull the IR cable up so that it’s sitting on top of the board. For reference, it’s the black cable that you can see passing under the fan and across the rectangular heat sink on p. 68. It’s very inconspicuous and likes to hide in the depths of the iMac case after the board is removed. The IR cable is also connected to the camera board connector so it’s easy to find its source.

This iMac belongs to my 91 year old dad and right now he’s using an old G3 12″ iBook running on an external drive that has a backup of the the iMac drive. Fortunately, the Apple Store just listed some refurbed 2010 Minis yesterday for $469 and I bought one for him. It should arrive in a few days.

By the way, I should add that for over a year this iMac had been showing a small rectangular box that followed the mouse pointer around (only with some applications and not others) and also had pixelated icons in the dock and on the desktop. At that time, I found one reference on Google reporting that Apple said this was due to bad onboard RAM and that the logic board must be replaced. Since it was only one reference, I blew it off, but now I believe them.

So the bottom line is that, in my opinion, if you have an iSight iMac that starts showing graphic problems or kernel panics (fans running full blast) and you’ve ruled out hard drive, system and added RAM problems, don’t assume that it’s necessarily due to bad capacitors. Take the iMac apart, remove the logic board, and examine all the capacitors. If you find no evidence of bulging or leaking capacitors, my advice to you is to save your money and put it towards another Mac.

Jim Warholic

To Bill,

Yes, there are significant issues with the iSight G5s. Many schools had purchased the first and second generation of iSight models, and are starting to have issues with lines through the screens and weird artifacts show up also.

I think a lot of these problems has to do with the design. Apple seems to have squeezed the thickness of the computer down to the point that heat is trapped in internal areas, which over time, breaks down connections between the main chips and the board. I have heard of folks trying the cooking of the board to see if they can re-establish a solid connection on the BGA.

Scott Waugh

Another point on the iSight G5’s, I believe those used nVidia GPU’s and Nvidia had a big problem with their manufacturing design (for a long time) leading to eventual failures of the GPU (look up bad bump Nvidia and you’ll find a load of stuff) over time. This was manifested most quickly in laptops with their enhanced on off cycles per day (lots of thermal cycling). I believe the iSight G5’s had nVidia GPU’s that were in this product group (which was quite large).

nVidia had to pay huge amounts of money to most of the main manufacturers for this problem (Apple included), but it can take a long time for the GPU bumps to crack and cause issues. If I had an iSight G5 and got a graphics issue, its mostly likely boat anchor time.

BTW, thanks for this page, I have my dad’s Gen 1 iMac G5 20′, the only issue is an audible tick (every 15 seconds to a minute apart) that happens when the machine has booted on a startup (volume and disabling the internal speaker in the OS has no effect) and when it comes back from low screen intensity (prior to screen off) to full intensity, very annoying (was thinking I’d just pull it open and unplug the speaker) but I noticed a bunch of distended capacitors (no blown yucky ones) and saw this page. Funny thing the tick seems to happen alot more in Leopard than Tiger.

Anyways, looks like I have a nice project waiting for me…and your pages are saving alot of computers from the heap.

Ilija Minovski

I have 17pc of IMAC20 (on motherboard is 2008 year) and IMAC24, I have problem with one IMAC20. Restarting in middle of work or not starting. Apple Hardware test – everything is OK. New RAM memory module, New HDD and same problem again.

Thanks and Best Regards
Ilija Minovski

Jim Warholic

To Ilija,

A few things to consider.

The Apple Hardware Test will not always tell you what is wrong. For example, it will not tell you if you have bulging capacitors in the PSU or on the main logic “motherboard.” The only way to tell this is to open it up and visually inspect those items. Refer to the Apple manuals for dis-assembly. Keep in mind, that capacitors can also go bad without showing signs of bulging. However, bulging is definitely a sign of bad caps. Additionally, if you have a meter, I suggest measuring the voltages of the PSU. This will tell you if any of the voltages are low, missing, or have excessive AC ripple riding on the DC voltages. Refer to my other articles that can be found on my Apple Information link.

Another area that is helpful, and can give good feedback as to what may be happening, is to install one of the free temperature monitoring programs. This can tell you if the iMac is overheating. Many times this can occur because the vents get clogged up with dirt, or one or more of the fans stops working, or even the capacitors themselves are failing and causing the board to heat up at these component areas or the PSU to have to work much harder.

Here are a couple of free programs that work well for monitoring the temperature and other key system items:

Temperature Monitor by Marcel Bresink
iStat Pro

Hope that helps you out.



Bosse Brason

Nice work! I wonder if you have any schematics and/or repair tips for a PowerMac G5 (late 2005) too? I intend to try to fix my brothers machine, but since I was retired I don’t have access to my former jobs schematics any more… The typt is API4FS13-291G.

Jim Warholic

Hi Bosse,

Thanks for the comment.

As far as any of the Apple products, I don’t believe Apple has ever released any schematics into the marketplace. As far as the PowerMac G5s, I have heard of many issues with the breakdown of the BGA (Ball Grid Array). In fact, some have written about the PowerMac having intermittent issues related to heat. For example, some will work only when it is cold, and others will work only when they are warm. In my estimation, there has to be some sort of connection type problem when this occurs.


Hi Jim,

Thanks for all instructions given on your site…

I am struggling with a small problem where maybe you know how to fix it!

I got this dead 17 inch iMac G5 (late model) and some caps where highly pregnant… yet it did start up with the fans spinning but no chime and no screen lighting up…

So I replaced them with some identical ones who where still looking OK from a different 20 inch iMac g5 (1st gen.) with a defective video card…


After putting it all back together but without putting most screws back in place, (just the mobo and frame connector ones) it does not startup anymore.

I tried both power supply units but the only LED lighting up is the first one… after the power cord is plugged in.

Both the internal and outer power button don’t seem to respond…


Do you have any suggestions about what possible went wrong?



Jim Warholic


I would be very leery of thinking the capacitors that you removed from another iMac are good. In fact, the process of removing the older capacitors, and the heat that is required to remove them from the board, could have damaged them. Not to mention that these are old capacitors, which would be highly suspect in having bad ones onboard both the 17 and 20 inch MOBs, even if the other caps are not bulging.

I would also verify your PSU voltages, regardless of if you think the PSUs are good or not.


Steve Wood

I have a iMac G5. I replaced all the obvious bad caps on the MOB. It will turn ON for maybe 20 sec, I get a chime, all the fans work, the CPU gets warm (I can feel the warm air from the fan)…..the video comes on for maybe a second….then it kinda goes into a sleep mode or something. I get all 4 LED lights on the MOB. The light on the front of the computer comes ON and then shuts off when the computer does its sleep thing or whatever it is.

Any ideas what is the problem now?

Jim Warholic

Hi Steve,

First off, you should always replace all the caps of both groups on the MOB. Even though, you only replaced the ones that were physically bad, I suspect you have others that are also bad.

I would also check the PSU capacitors too. Refer to my other articles at my Apple menu link for more information links.

Additionally, only the first three LEDs should come on. The fourth LED is over temperature. This can be caused by bad caps, fans that are not working, or a PSU that has too much ripple due to bad caps or other components.




I have a 1st gen iMac which after a Leopard install went kinda crazy…. After searching Google I found the symptoms I was experiencing were down to the logic board (starts up but with screen all messed up then crashes). I have taken the back off to inspect the capacitors but no sign of damage to any. How do I tell if a cap change will fix it and how do I tell bad caps? Thank you.

Jim Warholic

There are two areas where bad caps can factor into the problems you are experiencing. One is certainly with bad caps on the logic card, and the other area is bad caps inside the power supply. I would first inspect the PSU for any signs of bad capacitors. If you can measure the voltages with a meter, that is also another way of checking the PSU for excessive AC ripple on the DC voltage buses. Refer to my other Apple articles for more information on the PSUs.

If upon inspection, there are absolutely no physical signs of bad capacitors, then the only way to absolutely verify is to try replacing them and see what happens. Yes, there are low ESR meters that will sometimes work to establish a good or bad capacitor, however they do not always indicate properly due to other components in the circuits.

catherine mcneff

Hi, I have 12 vertical lines on my screen. I don’t even know what a motherboard is. I’m a fast learner. Can this be repaired? Seems like you’re saying it can. I have a iMac G5.

Jim Warholic

Depending on the exact model, this may or may not be a good candidate for capacitor replacements. The only way to see if the caps are good or bad is to open it up and verify the caps. Refer to the various Apple manuals for dis-assembly instructions. Also take a look at some of my other Apple articles for more information.

Chris F


I’ve got an iMac G5, 1st generation that would get the blue screen during startup. When running hardware check it noted no deficiencies. I attempted to install the OS again with no luck; the install appeared to go well but when restarting on the HD it went back to the blue screen, the hard drive ‘appears’ to be normal when looking at it on another machine via usb. No lines on the screens as noted above. The fans did seem to be running at a continuous high speed while stuck in the blue screen. The computer appeared to operate ‘normally’ when starting the install from the CD and during the install process as well as throughout the hardware check…no warnings, noted problems and nothing wrong with the screen displays.

Upon disassembly I note at least three bad caps (two near the L3001 inductor up near the fans, and C2203 near the L2001 inductor. All others in the group of ’29’ appear, visually, to be okay. None of the five ‘smaller’ caps appear to be bad either.

Do the mentioned symptoms match up with the ‘standard’ bad capacitor scenario and, do you believe that, replacing the banks of ’29’ will likely fix our problems?

Thanks for a fairly comprehensive page on this, apparently, widespread problem and how to fix it without shelling out excessive cabbage to either Apple or a repair shop.

Thanks, Chris

Jim Warholic

To Chris,

From the sounds of it, your descriptions of what is going on, and the fact that some of the caps are in fact bulging, it is highly likely the other caps are also bad. I have been seeing the capacitors that are actually dried out and are no longer filtering the voltages properly.

I would also check the PSU voltages and capacitors inside the PSU itself. Many times the PSU is also bad. Refer to my other Apple article links for more information.




Jim, thanks loads for all of the valuable information you’ve provided here on the iMac G5. It’s so insulting how Apple didn’t chalk up and acknowledge the problem with a recall, but rather to take a passive stance and help people only when they suffered a problem. As a result, numerous G5’s exist that have suffered this fault with no recourse possible through Apple.

I’m trying to fix a G5 that my sister owns. The first issue looked to be a hard drive failure. Running the disk utility would kick in the “You need to restart your computer” dialog. Also, running in single user mode and executing “fcsk -fy” showed errors but they couldn’t be fixed. When I took off the back, I noticed about 5 different capacitors are showing some leakage in the center of the (+) vent lines. None are bulging, though. Funny thing is, I went through a complete wipe and new install of OSX 10.5 on the system, but the failure dialog kept appearing at various points. I tried to narrow down the problem to memory, by leaving in only one of the two 1Gb DIMMs and running memory tests. With both cards installed, the Apple Hardware Test would suffer a script crash (a separate dialog would appear allowing only a shut down or reboot). Also, sometimes when I’d reboot, I’d get the flashing question mark on a folder, indicating a bad hard drive. But then a subsequent test using the Disk Utility showed that it passed!

Are these intermittent problems likely due to the capacitors being out of tolerance? Or, would a faulty hard drive manage to wreak havoc even when booting from a diagnostic DVD?

Jim Warholic

Hi Gary,

I agree with your thoughts on how Apple handled these problems. I think it was based what the bean counters had to say. They figured out what it would cost and simply decided to go the cheap route.

It does sound like the capacitors are bad (dried out) and probably are not filtering the voltages properly. Refer to my other Apple articles on the PSU for checking out the voltages and the internal capacitors on the PSUs. What can happen many times is the voltages will be fluctuating and then this affects the hardware tests. Additionally, if the voltages are indeed acting up, this can also cause issues with the hard drive too. See the article I wrote about the hard drive issue on the iMac.

Hope that helps you out.




Hi Jim,

Thanks for responding so quickly. 🙂

I have some good news… (fingers crossed, still). After several gyrations of trying different things, I ended up choosing one DIMM (1Gb) that seemed to coincide with fewer crashes and put that in slot 0. I then booted up off the install disks and did an erase/install from scratch. Miraculously, the system is working now. I’m able to use the Disk Utility without crashing (even fixed some disk permissions). I left the computer running idle for a good 15 minutes and no crashes.

Is it possible that one or more capacitors being worn out and slightly leaking will cause it/them to drift out of tolerance and then cause various things to go wrong, like HDD writing and memory access? I’m wondering if that’s what may have cause the HDD to become faulty to begin with. It’s old at this point, about 7 years strong now, so I wouldn’t be surprised if it was near the end of its life.

I’ll read over your articles on testing the PSU. I also downloaded the temperature app so I can check to see if things are heating up a bit too much inside. I do have a Fluke multi-meter; will that be sufficient to test the PSU?


Jim Warholic


I think it is likely that the voltages are varying for various reasons. It could be both the caps on the MOB as well as the caps inside the PSU. If the voltages are fluctuating, or possibly acting up under various loads then that could be the issue. For example, playing videos does place things under more load as compared to just sitting there in idle mode. Maybe even one of the memory sticks is more prone to voltage variances.

Yes, the Fluke multimeter will be more than sufficient to test the PSU. Actually any multimeter will work. I would check for both DC voltage levels as well as AC voltage ripple.



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