HP Integral : running !

Tony Duell ard at p850ug1.demon.co.uk
Mon Mar 14 16:58:54 CST 2005


>   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.
> 
> >
> >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.


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 
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



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