Hi all,
I have a G5 iMac RevA which is displaying some hinky behaviour of late

It started about 2 weeks ago where it would just throw up a random kernel panic every couple of days or so. Unfortunately they became more frequent very quickly though to the point where about a week ago it was 2-3 times a day.

Tried a couple of things like checking the hard drive for errors etc., which came back with no problems. I took the back off to check the RAM was seated properly (it was fine) and while I was at it I tested the machine with each stick individually (2 x 512mb sticks) in different slots, and always ended up with the same result (panics).

It got progressively worse to the point it would panic >5 times in a day, so I thought I would try re-installing Leopard to see if that cleared it up. Problem was, it wouldn't boot from the DVD at all, it just hung on the white screen with the Apple logo and spinning doo-hickey thingy.
Tried booting from the backup (external) drive also with the same result.

This was all last Saturday, so I turned it off and left it until yesterday so I could ring an Apple repairer to see if I could book it in. While I was on hold, I tried turning it on again, and was presented with a kernel panic immediately on boot, and it has been the same since then.
I now get the grey screen with the 5 languages telling me to turn it off etc., but I also get white on black text displayed down the screen as well with stuff like the kernel version etc.
(On a side note, I found it quite amusing that the last line was something along the lines of "panic: we are hanging here…" - Yeah, no shit…!)

I had it repaired in October under the repair extension program for power supply issues, and at the time they also replaced the logic board. When I opened it up to check the RAM, I noticed a very small amount of dark grey/light black gunk on the some of the capacitors, though they didn't look swollen or burst (not obviously anyway).

Anyway, does anybody have any idea what might be the problem? Does it sound completely buggered to any of you in the know?

Does it boot from one of the system install DVD's? You'll be booking it in if it doesn't, unless it turns out to be RAM, which you could test yourself if you have more than one stick installed.

No, noluck from the DVD (either the one that came with it, or the Leopard DVD)
I did try taking each stick of RAM out separately etc. with no change

Last shot - unplug everything except the power cable and turn of any wireless base stations and bluetooth gear in the house, including the BT keyboard/mouse if you're using one and see if it boots. Bit of a long shot as it sounds like your machine is dead, but worth a shot all the same.

i have the last imac g5 revision, my imac was behaving similar to this ... turns out my logic board was on the fritz, i didnt find this out until it completely shit it self ...

Sounds like dodgy or dead or dying logic board or power supply to me. (having eliminated RAM). I've heard of some of the 20" g5 imacs having a batch of dud logic boards that needed replacing after they shat themselves one by one, which was finally admitted by apple.

everyone else is right, all Imac G5 logic boards tend to fail this way, mine did after 6 months, then I got a REV B, it died after 12 months, so Apple Gave me a new Intel core 2 duo... it seems the G5 Imacs had big failure rates (up to 40%) so I think its time for a new mac, unless you can get Apple to give you a new logic board?

The logic board was replaced in October last year so if it is that, I would be hoping to have it replaced again under some sort of warranty.

Actually, no, I would hope that they don't have anymore logic boards available anywhere for the G5's and give me a new C2D iMac

Anyway, dropped it down to the Mac Doctors in Brissy today (they replaced the logic board and PSU last time) and now just have to wait I guess.

cool, let us know how you get on.....

Now I really hope it is dead! My boss told me today that if it is buggered, he will help me out to buy a new one
(well, I have been with him for 15 years, so I guess that counts for something)

Zap the logic board!!!

Result: New iMac!!

Meh 626

For anybody who is interested, it would appear that the Logic board that was put in in October was faulty, and has decided to go crap itself. Apparently it was the capacitors (that I had noticed with the crap on the ends of them) had buggered up.

So now the Logic board and PSU are being replaced again (under extended warranty program, though I thought that had finished already??) and I should have it back tomorrow/Thursday. Any thoughts on what I should do if it happens again? I know the thing is a few years old, but surely by now they would have sorted out their problems with the logic boards dying? I guess I'll just have to wait and see.

Funnily enough, our iMac at work (same model) hasn't missed a beat since we got it.

*touches wood…*