14 Mar
2005
14 Mar
'05
2:58 p.m.
Ah! OK now I'm following you. Yes the 9845 PSU
is a BEAST! I've worked on
It's one of the most complex PSUs I've ever worked on. I am not sure if
it's worse than the PSU in the 11/44, but ti sure comes close
a couple of them. I got lucky with my first one. The
wires on the large
heavy inductor had sheared off at the PCB board so it wasn't hard to fix.
Do you mean the black plastic block that's bolted to the metalwork that
also holds the transformer for startup? That's part of the mains input
filter, of course. Or one of the 2 main chopper transformers? Or one of
the inductors on the output PCBs?
I assume the first of those, and I really do wonder how on earth those
leads would come off in shipping.
I'm still not sure how they (UPS) managed to
mishandle it and cause the
wires to shear but not do any other damage.
I guess the thinking was that the Integral was a portable machine, and it
would be likely to get plugged into the wrong mains for the selector
switch setting. Plugging it into 115V mains when set to 230V does no
damage, the reverse could do damage to the PSU, so they put the
protection circuit in. It's overkill, perhaps, but this is an HP machine
There are no LEDs on the Integral PSU. The Integral PSU is a very
conventional SMPUS, actually. The only odd feature is that triac to blow
the fuse if you connect it to 230V mains when set to 115V.
I saw that but wasn't sure what it was for. That's carrying protection
to extreme. from the time when HP did things properly (unlike now
:-().
Does your Integral service manual make any mention of the 6 pin header on
the CPU board (Logic A PCB). From the labels, it would seem to be for
connecting a signature analyser, the 'data' pin is actually the A23
address line. I susepct thrre was a service ROM cartridge that fits in
place of the HPUX ROM too.
BTW Tony, if you don't object I'm going to save all these messages and
see about putting together a FAQ page for the IPC. I've been thinking of
putting up an IPC webpage for some time but haven't gotten around to it.
No problem. My view is that if I post something to classiccmp, it's been
made public (after all classiccmp is archived publically, I think). I
therefore have no problem with my postings being made public in other
ways. However, I do expect an acknowledgement somewhere on the web page
or file...
-tony