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.

Regards,

Jim

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

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.

Regards,

Jim

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.

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.

Jim

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.

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

Not referenced in the “service source”…

Thanks

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

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 ?

Thanks.

Best,

Michael
London, England

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.

Jim

There are significant differences between all the power supplies.

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

Thanks!

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.

Thanks,

Arnie