On 5/13/22 01:11, email@example.com wrote:
> Overheating is common and I'm aware of the process to try to fix it
> but my concern is that the machine has also become totally unstable
> in Open Firmware (OF).
> Initially OF was stable but I noticed that the machine had stopped
> chiming at power on and in the course of trying the various fixes for
> this OF has become totally unstable.
> I've tested the RAM (4 sticks of PC2-4200) in a PC with MemTestx86+
> and they are fine. I've also tried swapping in different RAM.
> I've tried all of the usual fixes, remove CMOS battery, power off
> for a day, clear NVRAM, boot holding down power key to go thru
> programmers tone into OF. This dinking is what made it worse :)
Sounds like bad capacitors  to me. Have you checked for any suspiciously
looking capacitors on the mainboard?
My first thought reading this thread was also capacitors. I'd check none are bulging/have leaked. Could also be capacitors inside the PSU so testing a known working PSU could also be quite a good idea.