Recap guide
Recap the iMac G5
Famous bad-capacitor failures hit the power supply and logic board, and Apple ran a repair extension.
Open the interactive checklist Tick off each capacitor as you replace it. It saves in your browser.
Worth a recap. Reports say it is a common and useful fix on this machine.
Which board do I have?
Boards changed during production. These notes come from the linked sources, and many are only partly documented, so check the board in front of you.
- iMac G5 Rev A (Medium confidence). How to tell: First revision. Capacitors: Bulging caps on the logic board causing shutdowns. Capacitor list differs from other revisions: not known. Source
- iMac G5 Rev B (EMC 2056) (Medium confidence). How to tell: EMC number on the serial label under the stand; 20 inch Rev B is 2056. Capacitors: Logic board and or power supply failures; Apple ran a repair extension from Nov 2006. Capacitor list differs from other revisions: not known. Source
- iMac G5 Rev C (iSight) (Low confidence). How to tell: Redesigned case with heat parts at the top. Capacitors: The threads do not report a cap problem for Rev C. Capacitor list differs from other revisions: not known. Source
Where to start
Clues from write-ups and forum threads, not a diagnosis. Low confidence means one thread or one repair; high means several write-ups agree.
- Bulging caps (Low confidence). One iFixit story confirms the failure pattern on the power supply and logic board, but the machine was fixed by swapping the PSU, not by recapping. Source
Tips, tales and maybes
Found in write-ups and forum threads. These are other people's reports, not tested by us. Check part references and values against your own board.
- Tip: Fuzzy boot screen: check 24 caps, then the GPU (Medium confidence). An iFixit answer for an A1058 with a distorted screen that clears after boot says to remove the bottom frame and inspect the 24 capacitors for bulging or corrosion, and to replace all the bad ones. It also offers a GPU solder joint reflow as the alternative cause. Source
- Tip: Flat tops only and swap the PSU to test (Medium confidence). A thread says healthy cap tops should be perfectly flat and even a slight dome means a bad one. The owner's machine cutting out mid-boot was fixed by replacing the power supply, and the advice was to test with a known-good supply because both parts can fail independently. Source
- Watch out: Good-looking caps prove nothing on a G5 (Low confidence). A MacRumors reply said nice-looking capacitors are no proof they have not failed on a G5, and the advice to an owner with a dead machine was to pull the drive and move on rather than repair it. One opinion, but it matches the visual-inspection caveat above. Source
Before you start
- Boards changed during production. Check your board number against the guides before you order parts.
- A mains power supply can hold a dangerous charge. If you are not trained to work on one, have a professional do it.
Guides we used
This page and the interactive bench are built from these. They have the photos and the full detail, so please read them and support their authors.
- My iMac G5, Back from the Dead (Write-up) by noahguadagni on iFixit. Fixed by swapping the PSU; confirms the failure pattern but not a recap list
The capacitor list
We have not checked a capacitor list for this machine yet, so none is shown. Follow the guide above for your board, then add the capacitors in the interactive checklist and it builds a shopping list for you.
Skip the sourcing
While you are in there
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Steps, tools and safety
The steps, the tools in top, middle and budget picks, and the safety list are the same for every machine, so they live on one page: How to recap, step by step.
Values are shown as published in the guides above, and boards changed during production. Check the board in front of you. A recap involves hot tools and, on some machines, dangerous voltages. You do it at your own risk.