Rebuilding the PDP 11/34 (2volts?)

From: Mike Kenzie <>
Date: Sat Oct 6 08:16:49 2001

----- Original Message -----
From: "Tony Duell" <>
To: <>
Sent: Tuesday, September 18, 2001 1:39 PM
Subject: Re: Hardware races

> > A few questions remain.
> >
> > What would be the best way to test the Power supply it is
> > 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
> behind the backplanes. This needs to be connected to the PSU for
> otherwise the regulator blocks are not electrically connected to
> (they connect via this PCB and its associated wiring). You can
> 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)
> refit the PSU to the back of the CPU box.
> Then, with all the plugs in the PSU, and the backplanes
> power up the machine (plug in, turn on the breaker on the back, turn
> the knob on the frontpanel). The PSU contactor should pull in and
> fans start. You can then check the PSU output voltages at the
> power sockets on the distribution board. Do check the voltages at
> 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
> 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

8" morrow floppies without cables or controllers
Received on Sat Oct 06 2001 - 08:16:49 BST

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