During the transition I had to reset the SMU to deal with one of many causes of the G5 non-stop fan problem (CPU sure was cool though - 60 C). I also popped the case to blow massive amount of dust off the fan and vent. I love the user-serviceable plastic case design; it was a high point of Apple customer-friendliness.
When I popped the case I checked the capacitors. In one of the many sordid bits of Apple hardware history they shipped a bazillion iMacs with flawed capacitors. Many of those failed under warranty, but Macintouch tells us they continue to die over time. A lot of iMac buyers lost some loot there. (I wonder if the iMac's original fan/heat problems contributed to this.)
I just checked mine and I didn't see any bulging, but it's worth noting that there's now a small G5 iMac capacitor repair/replacement industry ...
Macintouch - iMac G5
... Late last year one of the other guys at work started repairing iMacs on the side, replacing the swollen caps. He gave me a full set (since I had given him the idea in the first place when mine failed, I think) and said "give it a try" with a few pointers. I replaced all the caps over a weekend and now I have a fully functional iMac G5 in my workshop to replace the 8500 and 7300 that were there... Check around locally for smaller tech shops. In South East Wisconsin, MacCetera does the repair for a flat rate of $200 + tax, including parts.
... My iMac G5 suffered a swollen-capacitor death two years ago. Once they were replaced it has been running smoothly 24/7 as a database/Web server and Skype phone.
... The owner of www.badcaps.net performs motherboard capacitor replacements on G5s. It'll run you less than $75 for a premium capacitor rework.It's worth checking out the site if you're considering getting a 3rd party to perform this repair. They also have a knowledgeable tech forum that has discussed many G5 hardware issues.
- iMac G5 fan noise: another cause (before Apple's software fix worked)
- iMac G5: fans running more often
- Bad fan design is the bane of the iMac G5 and Silencing the G5 whine: I think this was fixed by my version - iMac G5 rev 2: a lot cooler?
- Fix for 10.4.3 fan problems: unplug and restart and resetting the SMU (PMU?)
- iMac heating problems and the curse of the Canon printer driver and (one of my most popular posts) My MacBook fan was roaring. Why? - evil OS X drivers.
* When I do these reviews of old posts, it strikes me that before the wonders of Google Custom Search I tended to discover and forget things -- and I was younger then!
Update 12/18/2011: "Cordwainer" (Karen Cotton) has written an extensive comment on the story of the capacitor failure. Worth a read. I still use that G5, and the capacitors still work.