Whitechapel MG-1 workstation questions

From: Bernd Kopriva <bernd_at_kopriva.de>
Date: Sat Apr 24 17:25:14 2004

Hi Jules,
unfortunately, a PC power supply won't work, as the red one delivers 24V
which is needed for the monitor (again, that't from Tony Duell, who seems
to know almost anything about that beauty ...).
I had a used Astec LPQ252 as replacement, but that has been defective
as well, so i had no luck until today ...

Bernd

On Sat, 24 Apr 2004 22:09:49 +0000, Jules Richardson wrote:

>On Sat, 2004-04-24 at 21:20, Bernd Kopriva wrote:
>> Hi Jules,
>> i got that one formTony Duell some times ago :
>
>[snip]
>
>thanks for that.
>
>> Btw: do you have a spare power supply (or maybe some schematics) ? Mine
>> is dead, so i never got my machine up and running :-(
>
>The machine I've looked at so far has a good PSU, but the track on the
>power distribution board that feeds +12V to the system board is totally
>burned away, and someone had bypassed it with a piece of wire. Obviously
>the system board has suffered some major short at some point - I'm yet
>to find out if the bypass wire was added after they fixed the fault or
>not!
>
>In other words, it's possible one system board is completely dead, in
>which case yes there could well be a spare PSU. Depends on what state
>the system board is in this machine, and whether the PSU in the other
>one works or not; idealy getting two machines working would be nice!
>
>You could always use a standard PC PSU I expect. There's six different
>lines running to the PSU in these Whitechapels; GND, +5V, +12V, power
>fail are four of them. The purple wire I expect is -12V. That leaves a
>red wire, which would seem a strange colour to choose for a negative
>voltage. Maybe it's +15V or something odd, perhaps for driving the
>display. I'll let you know when I work it out :-)
>
>cheers
>
>Jules


Bernd Kopriva Tel: 07195 / 179452
Weilerstr. 24 E-Mail : bernd_at_kopriva.de
71397 Leutenbach
Received on Sat Apr 24 2004 - 17:25:14 BST