Chosen Solution
I’m playing with a Quad Core PowerMac G5 (A1117). So far everything was fine, I’ve reworked all the thermals and the machine worked well for more than a week under high load, compiling non-stop. Today I’ve turned it off and after several hours tried to turn on. But it doesn’t POST anymore - checkstop led (led #7) blinks twice after power on, then waits, then blinks twice again. I’ve tried to pull out the RAM and graphics card - no change. Tried to power on without CPU module at all - well, as expected it turns on CPU leds. Video: https://youtu.be/fHsGQON55CM Would be grateful for any hints what may it mean.
With an experiment I figured out what it means. Double blinks mean that CPU B misbehave, single blinks mean that CPU A misbehave. Most likely I’ve damaged my CPU B while working on thermals. By the way, 2.5 gHz 630-7419 CPU card seems to be interchangeable with 2.3 gHz 630-7418 - I replaced broken 630-7419 with 630-7418 and it worked without an issue.
