[rescue] SPARCserver power supply
brooknet at imap.cc
Sun Dec 19 12:09:31 CST 2010
The 630MP power supply saga continues!
Having run continuity checks on my 630MP's lines, I've verified that my
original pinouts were correct (touch wood) - but some damage occurred
when I first powered up the replacement power supply, and I found that a
capacitor (C55) on the backplane had blown; this caused damage to the
RAM chips of the cgthree card and it now shows a corrupted screen.
Could any electronics experts please make a guess at what could have
caused this? A guess: something similar happened with my Apple II; I
used a replacement PSU there too, and the RAM chips required the -5V
line to be active before the rest of the lines. When I used a new PSU,
the -5V line powered-up at the same time as the other lines, causing the
RAM to eventually fail. In that case, the chips didn't short-out, but
just died. I'm wondering whether the SPARCserver issue is related or
whether this is a case of 'silicon latch-up'.
Thanks to Simon for the VMEbus connections.
More information about the rescue