6 Oct
2001
6 Oct
'01
1:16 a.m.
----- Original Message -----
From: "Tony Duell" <ard(a)p850ug1.demon.co.uk>
To: <classiccmp(a)classiccmp.org>
Sent: Tuesday, September 18, 2001 1:39 PM
Subject: Re: Hardware races
power
> A few questions remain.
>
> What would be the best way to test the Power supply it is
currently
off the
chassis, does it need to be connected for testing?
In the 11/34 (I assume this is a
10/5" BA11-K cabinet), there's a distribution PCB running across the main part of the
box on the
bottom,
behind the backplanes. This needs to be connected to
the PSU for
testing,
otherwise the regulator blocks are not electrically
connected to
anything
(they connect via this PCB and its associated wiring).
You can
either
remove the PCB from the chassis or just unplug the
backplane power
connectors from it (to isolate the rest of the machine from the PSU)
and
refit the PSU to the back of the CPU box.
Then, with all the plugs in the PSU, and the backplanes
disconnected,
power up the machine (plug in, turn on the breaker on
the back, turn
on
the knob on the frontpanel). The PSU contactor should
pull in and
the
fans start. You can then check the PSU output voltages
at the
backplane
power sockets on the distribution board. Do check the
voltages at
every
power socket -- IIRC the +5V rail (at least) does not
run across the
entire machine -- 3 of the sockets come from one regulator and the
other
2 from another regulator).
Got it reassembled and turned the switch, the lights came on and the
voltagages tested at +-15, +5 and one at +2v
We were expecting the 15 and 5 but not the 2 is this just an artefact
of testing with the unit partially disconnected?
Found empty connectors on the M7891 and M8265 cards what would have
attached to these?
Also have a few BC11A cables for connecting the units but the main
unit seems to have all the slots filled and a terminator at the end.
There are several unidentified cards still remaining
versatech 289 380211 with 2 teledyne philbrick 4023 10bit D/A
convterers
8" morrow floppies without cables or controllers