Apple iMac G5 Take Apart Procedure 1st and 2nd Generation

Here is the procedure that I used to replace the capacitors on the Apple iMac G5 MOB.

Here is the link location of the Apple service manuals, with step-by-step instructions in PDF document form for removal and replacing everything on iMac G5 computers and other Apple products including: Cinema Displays, MacMinis, Laptops, eMacs, iPods, iMacs, and Towers. (link opens in new window)

When you take it apart, start with this order:

  1. Lay the iMac face down on a soft, protected surface.
  2. Back cover removal. (Loosen the three screws on the bottom lower edge, then lift up carefully from the bottom up).
  3. Take close up pictures of your G5 mother board and inside the iMac for your reference in case you need to refer to something for proper installation.
  4. Power supply removal ( ).
  5. Verify Power Supply capacitors are not bulging or blown out.
  6. Hard drive removal.
  7. CD removal.
  8. Memory cards removal.
  9. Right fan cover removal.
  10. Lower left two small plug connectors undo by carefully taking needle-nose pliers and tug the plugs upwards to disconnect them.
  11. Fan plugs – disconnect.
  12. Airport option removal, being careful not to break the very delicate antenna wire clip. You might want to leave the wire attached and just move the Airport out of the way.
  13. Then remove the Torx mounting screws. See the special 12-in-1 screwdriver with Torx and Phillips bits.
  14. Carefully lift out the MOB, making sure all the mounting screws were removed. Do not force it.
  15. Heat up the soldering iron, with a wide tip attached, and working from the bottom and the top of the MOB, with the MOB tilted up on edge, heat up one leg of a capacitor on the backside and rock the capacitor slightly from the top. Then do the other leg, and the cap will come out of the hole.
  16. Remove all capacitors in the groups.
  17. Once the holes are clear, (pins work well), then place the high quality low ESR capacitors in the holes, making sure the positive and negative legs of the capacitors are properly situated in the holes. Do not install caps backwards. Major damage will most likely result.
  18. Apply Arctic Silver thermal paste heat sink compound to the small area (make sure it is cleaned with isopropyl alcohol), on the bottom of CPU. Cover it and the matching heat sink area with a thin layer (not to excess). Use a small razor blade as a scraper to remove the excess. Keep it thin, thin, and thin.
  19. Reassemble the motherboard, (don’t forget the white light tube that displays the “power on” light on the front cover of the iMac), hard drive, DVD/CD Super drive, cables, plugs, fan covers, memory modules, and make sure you don’t have any extra screws left over.
  20. Double check and triple check your work.
  21. Place the back cover on.
  22. Plug everything back in and turn it on.

Important Notes:

  • Don’t forget to put new heatsink compound back on the bottom of the processor chip, which is located on the bottom of the MOB, and the solid plate heatsink assembly located on the chassis: Arctic Silver. Several heating up and cooling down cycles is required for maximum thermal heatsinking effectiveness.
  • At least a 60 watt soldering iron is recommended and a good solder sucker and some plastic headed sewing pins for heating up and push removing solder from holes. Read the article: Soldering Tips for Lead-Free Solder for more detailed information.
  • Use rosin core solder only. Do not use acid core or acid flux. Use lead free, or, in my opinion even standard 60/40 leaded solder will work (although there are few lead-free caveats) for soldering the new caps. Just make sure there are no cold solder joints.
  • How to Tip: Use a few small pins to clear the holes when the soldering iron is used to heat up the holes to remove the old solder.
  • Don’t try to bypass this advice. Highly recommend replacing all the caps in both groups. Even though one or two caps might be visibly bad, the others are more than likely weak or on their way out too.
  • It’s up to you if you want to attempt the repair. It depends on how comfortable you feel about doing it yourself. The degree of difficulty on MOB caps replacement on a scale of 1 to 10, with 1 being the easiest and 10 being the hardest; a 7.
  • Double check your power supply unit. Open the PSU to check those capacitors too.
  • Degree of difficulty on PSU caps replacement on a scale of 1 to 10; a 3.

The procedure above is going off of memory.


  • Layout your screws as you go.
  • Have lots of room to lay it out.

Refer to my articles, read carefully, and suggest printing them out for reference.

iMac G5 Motherboard repairs procedure
iMac G5 power supply repairs

Feel free to contact me if you have any further questions.



Your instructions are very complete, therein lies a bit of confusion. I see where on reassembly I need to put heat sink paste on the CPU and heat sink, but I don't see where you mentioned taking off the heatsink or exposing the CPU. It would help to know this as I'm about to disassemble the MB very soon and don't want to miss anything important.

Jim Warholic

The CPU is actually attached on the bottom of the motherboard and is not removable. Note that the heatsink and the CPU are not like a typical PC computer assembly. On the Apple iMac G5 1st and 2nd generation models, the solid plate heatsink is mounted to the chassis. So, when the MOB is unscrewed from the chassis and removed, it exposes the heatsink, with the heatsink staying attached to the chassis. The MOB with the CPU comes off as one piece. Do not try to separate the CPU from the MOB. The CPU is soldered to the motherboard.

Hope that clarifies it a bit.

When the MOB is removed, the heatsink and the CPU can be cleaned of the old heatsink thermal grease with alcohol prior to applying new heatsink thermal compound.


I have the g5 17″. Apple’s instructions for the lower fan removal are for the “ambient light sensor” model only. I am having difficulties getting this thing out. There is a metal piece that lifts up, but no matter how hard I push or pull this cheap bugger won’t give. What’s the deal? Thanks, btw love this site.

Jim Warholic

Hi Steve,

I think I might have mentioned this before someplace, but it is good to post this here too.

Apparently to remove the fan on the G5 non iSight models, it looks like the speaker is in the way of the bracket being able to lift up that holds the fan in place. I found the following information in this link to the Apple forum area for how to go about removing that lower fan on the non iSight G5 models.

Scroll down until you see the following posted information:

Re: How to replace lower (CPU) fan in Rev. A iMac G5
Posted: Dec 29, 2009 12:20 PM

The forum poster mentions about removing the power supply, three or four screws on the inner frame (see a following posting), two long screws on the bottom located below the logic card that screws into the front bezel, and removing one speaker. The speaker is held in place with two screws too.

Quote #1:

Yes I see what you mean. I have a 17″ iMac G5 here now all taken apart. Logic board, HD and power supply out.

So the fan keeper only lifts straight up. You can’t get the lower fan out because the speaker housing is in the way.

The power supply must be out but the logic board can stay as well as the HD.

You remove three screws at the top of the inner frame. They’re between the outer white housing and the inner metal frame. There are also two long screws at the bottom lower left and right of the logic board. These have to be removed as well since then go thru to the front bezel.

Lift up the top of the inner frame and the entire inner frame will lift up. Don’t remove it too far as the display cable and the airport cables are still attached.

With the inner frame up, you can reach under and remove two screws holding the speaker in (T-10). The speaker pulls out over the locking shaft for the back.

With the speaker out you can lift that fan lock up and the fan will slide straight out the bottom.


I’m pretty sure that’s all the screws but don’t force it. If you have a problem post back. I have to step out for a bit and will check here when I get back.

Quote #2:

Oops there’s another screw just below the left locator pin. So that’s just left of the speaker and headphone ports.

Hope that helps.




Thanks Jim for the thorough description. I thought I would need to remove the lower fan out in order to remove the motherboard, but to my surprise it came out just fine with the fan still in. But I’m sure your detailed instructions will benefit a frustrated individual somewhere.

Arnold Zunick

Hi Jim…
I received the replacement capacitors for my 17″ iMAC G5. Thank you.
I was in the electronics business for may years and soldering was second nature to me. The new solder with a higher melting point is a problem

I took apart the MAC without any problems and setup my soldering station using a chisel tip. Using solder wick and liquid rosin I’m having an extremely difficult time. Removing the old “caps” and clearing the holes is a real project. I think the iron is hot enough and I managed to get 2 caps out in an hour, but can’t clear the holes. At this rate, replacing the caps will be a whole new career.

Any hints or clue that could make the processes easier will be greatly appriciated.



Jim Warholic

I strongly suggest reading my lead free soldering tips article. If you are looking for some ideas for a good quality soldering iron or soldering station for a reasonable price, feel free to write to me and I will provide the suggestions. I also suggest ordering the Chip Quik from my online eCommerce website. This will make any job much much easier when dealing with lead free soldering repairs.


Hi Jim,

I would like to switch my G5 mob with a 2.16GHz Core Duo mob
(compatible with snow leopard?) that doesn’t power on. The seller
doesn’t know why.

Is the G5 power supply compatible with the Core Duo? The working G5 iMac
has the following designations:

Model Name: iMac G5
Model Identifier: PowerMac8,2
Processor Name: PowerPC G5 (3.0)
Processor Speed: 2 GHz
Number Of CPUs: 1
L2 Cache (per CPU): 512 KB
Memory: 2 GB
Bus Speed: 667 MHz
Boot ROM Version: 5.2.5f1
Serial Number (system): W85197HHSDY
Hardware UUID: 00000000-0000-1000-8000-0011243BE39C


Laura Morton

Hi Jim – Thanks so much for all of the extremely beneficial information. I have a 20″ first generation iMac G5 with a failed logic board. I’ve gotten all the way through your instructions for removal, and would be able to lift it out except for one small wire in the lower left “nook” of the board. It emerges from the small hole in the lower metal frame, and attaches to the board almost directly above that underneath a small, raised chip. Can you please tell me how to get past this? I am by no means an expert (but don’t worry, I’ll be sending it out for repair – it’s just less expensive to send the board alone as opposed to the entire computer), but have found success in the “minor” things like removing parts. This is the only thing hindering me from getting the board out – please help! Thank you!

Jim Warholic

Hello Laura,

The wire/cable that you are referring to is probably for the wireless Airport card (which looks like a big rectangular chip) or the bluetooth. The cable is a miniature coax cable that typically goes underneath the main motherboard, and then heads up to the top, where the antennas are located.

As far as removing this cable from the onboard Airport card, I actually recommend removing the Airport card with the cable attached. The cable connector typically has a pull tab, but on the older iMacs, the plastic pull tab is old and brittle and breaks. Then, it becomes quite difficult to remove (first hand experience here) the miniature connector, and is easy to break the connector. If you leave the connector attached to the card, you can then remove the card and just lay it toward the side with the cable attached. You might need to remove the plastic support housing for the Airport card in order to swing everything out of the way.


Michael Thorne

Hi Jim,

Very useful info, but I only need to replace the LCD screen in a 20″ iMac G5.

Will I need to get into soldering, thermal paste, and all that, or is the screen swap a fairly straight-forward procedure ?

I’ve done a few DIY Mac jobs, including replacing the hard drive on a MacBook without a single screw being left over, so I’ve got a fair idea of what I’m doing, but I’d feel wary of getting into a soldering job.

Does anyone know if there are instructions online ?



London, England

Jim Warholic

Depending on what model you have, you might have to take it completely apart to get to the screen itself. When operating on newer iMacs, the screen is the part that gets removed first. With older iMacs, you kind of have to remove everything else to get to the screen. I found the following link with all the Apple service manuals, with step by step instructions for removal and replacing everything on G5 and other Apple computers.


Hi Jim,

Your guide is very detailed and very organized. i need to replace my processor fan. i already have the replacement one but the fan cable goes under the motherboard and I was wondering if you could give me some help on removing the processor fan cable which looks to go under the motherboard of my first generation iMac G5…emc number is 1989.. thank you.

– Kenneth


How to remove the power supply from my IMAC G5 VIN,iMac G5 (20-inch)?
MEID : IMEI : Numéro de série : W84431JCPNZ first generation ?

Not referenced in the “service source”…


Jim Warholic

To remove the power supply unit “PSU” in the first generation iMacs on both the 17 inch and 20 inch models is fairly simple. First, place the iMac face down on a table top with a soft cloth for padding. Then remove the back of the iMac by turning the three screws counter clockwise till they stop. Note, they will stay in the holes. Once the back is off, then you have access to the PSU. Turn back the center screw halfway to the stop clockwise. This is so the PSU will clear the screw itself when removing the PSU from the case. Next, loosen PSU mounting screws. Remove the connector between the PSU and the logic board (also known as motherboard). Note that sometimes the plastic case may need to be tweaked out ever so slightly (only slightly) in order for the PSU to clear.

Once the PSU is loose, then it can be tilted up and out from the case. Refer to the various Apple tech manuals.


Used the guide here to to motivate myself into replacing one cap. Yes, I know I should replace all. Thanks anyway.

Had success with a $15 USD Weller pen iron. Tip was clean and warmed for 5 mins before I started. Took two tries, on each wire, rocking the cap gently while the solder was puddled, before it fell free. 2 minutes of tool time. And yes, I do plan on using the same iron to successfully install the new cap.

It can be done and done well, with inexpensive, even cheap, equipment.

Jim Warholic

Hi Joel,

Yes, it is always a good idea to replace all the caps when finding even one bad. It is pretty much a given, if one is bulging, the others are weak and not filtering the voltages properly. It will result in the one cap having to do most of the filtering work, and thus actually weakening the new one quite quickly, while the other caps also are in a state of not functioning at peak performance.

A couple of points on the soldering. If the soldering iron does not recover quickly on the heat, and it becomes necessary to keep it on the new capacitor leads for an extended period of time, the new capacitor could become heat damaged. Also, some of the logic circuit boards used by Apple seem to be able to melt the solder with a typical soldering iron easier than others. However, most times, it requires high heat from the soldering iron to melt the lead free solder.

Just to also put things in perspective, it is wise to consider that the job requires a bit of patience and realistic expectations. I have repaired a number of the iMacs, and depending on the condition of the capacitors, they can be a bit difficult to remove, especially if the capacitors are already heat damaged and the legs are actually loose inside the body of the cap. The leads will tend to come out of the capacitors themselves when heating them up with a soldering iron.

For more information please read my article on lead free soldering for tips and hints.


Frank Flavin

My sincere thanks for your wealth of knowledge.

I have a iMac G5 purchased 08/05/05. Apparently the video card failed,was getting strange patters in my photo editing. I went to Apple and they were more than happy to sell me a new 26″ iMac. They did transfer most of the files for me but not all for some reason. This was 2 months ago. I tried to fire it up to get some info they did not transfer. It powers up welcome sound, screen lights, spinning disc but then goes black. Is this an easy fix or is it toast?

It seems a shame to just discard. It did serve me well. I’m not much of a tech person so should I contact a repair guru or give it a shot on my own ? Apple had told me that parts were probably not available. Thanks Jim and look forward to your reply.

Jim Warholic

Thank you for your comment.

Here is what I would do. I would first check the logic board for any bulging capacitors. Then I would take the PSU out, and also check inside the PSU for bulging capacitors. If no bulging capacitors are seen, then I would check the voltages on the PSU with a meter. Refer to my other Apple article links for more information.

If you have tried all of those things, and yet the monitor looks weird, then it is possible that the graphics chip or other related IC chips are bad on the logic card. If that is the case, then it probably is not worth sending it out for repair unless you get some form of commitment as to what the costs would be to repair it, though you might be able to get some money for it as a parts machine selling it through a local Craigslist.

Additionally, if you need to get the rest of the information off the hard drive, you can remove the hard drive (you might want to do this anyways to keep your data secure) and use a USB adapter to plug it in to your new computer, and it will show up on your desktop as an additional drive. You can then transfer the files to the internal hard drive. Refer to my article on the Universal Hard Drive Adapter for more information on using the adapter.

I strongly suggest that everyone start using an external hard drive to backup their laptop, desktop Apple computers, and PCs on a regular basis.





I removed the rear cover and the 5 caps you showed on the board are bulged. The power supply caps are fine. My question is can I remove this board to R/R the caps from the rear? The IMAC manuals show every thing from the front. If you could let me know it would be great.

Thanks Steve

Jim Warholic

Hello Steve,

Yes, you would need to remove the main logic board in order to replace the caps. To do so, requires removing the mounting screws that hold the main logic board in place. There is no need to remove the main heat sink with the G5 logo on it. Keep that attached to the main logic board. There will also be various plugs and cables that will have to be removed in order to completely pull out the motherboard. I suggest removing the memory cards too. Also, suggest keeping track of where all the screws go.

I believe the Apple service manuals show the locations of the mounting screws, but be aware that some of the screws are different sizes. Here are the Apple service manuals for disassembly. Go to the section of the either the 17 or the 20 inch (depending on which one you have) and location the Logic Board Removal instructions.

Refer to my removal and replacement instructions above for more details on the iMac G5 repair procedures.



Rob Tripp

Hi Jim,
This is another of those G5 iMac problems…. A 2004 17″ PowerMac 8.1, with a PowerPC G5 (3.0), 1.8 GHz, 512KB, 2GBDDR SDRAM, running @ 600MHz.

It’s had the bad caps problem sorted by the Genius Bar to the tune of a new logic board! But over the past year or so the lower fan has begun to speed up after a period of use, maintains high speed for a while, and then the computer goes to sleep. The period of normal use has shortened from over an hour to now 5 mins, with high fan speed usage 10 – 15 mins. A tap on a key or mouse wakes it again, but the awake time then depends on the time spent asleep. The activity monitor shows the high CPU usage to be the dashboard client >7%, and activity monitor <6%. The LEDs 1-3 show perfect behavior, and 4 does not light. There is no other fault in operation.

Best regards,


Jim Warholic

Hi Rob,

I would dive into the PSU and see what those capacitors look like. The runaway fan is indicative of the power supply having lots of ripple voltage, and causing things to heat up, especially on the older G5s. Also, with the wake-up situation being an issue also, that tends to point to more of an issue with the power supply. By the way, I’ve said it before, just because the computer turns on, does not mean the power supply is good. Refer to my other Apple articles in that realm for more details.



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