26 Mar
2010
26 Mar
'10
1:34 p.m.
The PSU of the HP9000 C240 / C360 are prone to this. A
few friends and
Which is the HP9000/240? Sounds like its ought to be a 9000/200 series
machine, but it's nto one I've ever come across.
I had that problem. Several dead machines that would
start only
sometimes when pluged in. Verry frustrating. Eventually a friend took a
weekend to reverse engineer the PSU and finaly found the faulty
resistor. We changed that resistor on all of our machines and they
work flawlessly since then.
I was given an HP9144 tape drive beucase it was totally dead. After
removing the conver and front paenl I found all PSU outputs were missing.
So I slipped out the PSU board and had a quick look. The chopper was
fine, nothing looked burnt and then I noticed a pair of (IIRC) 100k
resistors in series. Aha, I thought, that looks like the startup
resistor. One tested open circuit, so I replaced the pair for good
measure. And it's been fine ever since. It took me under an hour to fix,
never having seen one before...
-tony