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G3 iMac 400 power troubleshooting
Posted by: RickNel on 2013-10-04 05:11:33
I've been given a strawberry G3 iMac 400/DV that is nice and clean but won't power up. So far I've replaced PRAM battery and tried pushing the CUDA switch. On one occasion the power-on button flashed for less than a second, but generally nothing fires up. I do hear a pop in the speakers, which suggests there is some power on the board but not enough to boot. Display remains dark.

Any suggestions on a troubleshooting checklist? Could this be a caps issue?

Rick

Posted by: bibilit on 2013-10-04 05:55:15
Any suggestions on a troubleshooting checklist? Could this be a caps issue?
Yes can be, you can probably find the service manual online, it's pretty well done... will help troubleshooting any issue.

Posted by: RickNel on 2013-10-04 16:16:26
I just saw Didius' thread on what sounds like very similar G3 problem.

http://68kmla.org/forums/viewtopic.php?f=13&t=21863

A great save by Didius 😎

Looks like I have a major re-cap to consider. This "free" G3 iMac could end up costing $$$. But it is a pretty machine, pink and rounded, and hard to resist its charms.

Rick

Posted by: CC_333 on 2013-10-05 15:17:21
It might be easier (and less labor intensive) to just replace the analog board with a known working pull from another iMac (such as one who's CRT is smashed and/or who's plastics have crumbled.) How you choose to proceet is pretty much up to you, though.

Anyway, however you choose to proceed, I wish you luck!

c

Posted by: didius on 2013-10-06 02:32:22
The hard part is cracking it open and getting the PAV board out... Replacing the caps or replacing the board is just a choice...

I found replacing the caps was pretty easy. There are a lot of them, that's true, but hey isn't reviving these macs a fun hobby?

It takes some time, but i found replacing the caps easier then getting the PAV-board out and back in...

Posted by: RickNel on 2013-10-06 03:33:17
To repair or replace is always a fair question, but location is a big factor. I see working G3 iMacs advertised for $5 in California, but in my location to get parts from anywhere adds $40-50 freight to the cost, even for a logic board, and working units are rare locally. Nobody seems to bother parting out G3 iMacs in Australia.

The main risk in starting a major re-cap is that I could get to the end of it and then find the problem was deeper, say a failed PMU/CUDA chip. Anyway, while I wait for a logic board or working iMac to turn up at reasonable cost, I'll disassemble this one and see if I can see any evidence of other probs, before investing in the re-cap.

Rick

Posted by: didius on 2013-10-06 06:10:23
Somewhat an identical situation in belgium 🙂

Keeps us updated! Perhaps you could try the pin-readout I posted?

Posted by: RickNel on 2013-10-06 14:54:33
I'll be following your experience closely, but not necessarily quickly. Yes, I'll report back when I make any progress.

Rick

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