PDP-11/83 Power Supply Wierdness

From: Kevin Handy <kth_at_srv.net>
Date: Wed Sep 10 11:34:00 2003

Christopher McNabb wrote:

>On Fri, 2003-09-05 at 14:08, Kevin Handy wrote:
>
>
>>Christopher McNabb wrote:
>>
>>
>>
>>>My PDP-11/83 has recently (past few weeks) been displaying some odd
>>>symptoms. The system is a PDP-11/83 in a "Corporate Cabinet". Most of
>>>the time, when the power switch is turned on, the "run", "halt", "ready"
>>>lights blink on then go off. Also, the Red light on the TK-50 will come
>>>on then go off. You also hear a relay closing and opening in the rack
>>>power supply.
>>>
>>>
>>>
>
>OK, after playing around with it tonight it looks like the problem is in
>the on/off switch on the BA-23 box. If I push on the switch REALLY hard
>then the system will stay on. If I let the pressure off the switch it
>almost immediatly shuts off.
>
>So, anyone know where I can get a replacement switch?
>
>Does anyone know how the switch is wired so that I can jumper it should
>a replacement not be available?
>
>
>
Until you can do a proper repair, I think you can just unplug the
connectors on the back of the switch and short them together to
have an always-on setup. Make sure to cover them with electrical
tape to keep them from shorting to the case. (I think there are only
two wires on the switch.) You can then turn on/off the machine at
the distributation panel in the bottom of the case (flip the big
ganged black switch).

The switch should be the same as the one used in the BA23 boxes.
There should still be a lot of those boxes around, so someone should
have a dead box that they could scrounge a switch for you.

Anyone have the proper part number? I'd guess you should still
be able to order one from somewhere. Maybe also ask on
alt.sys.pdp11.
Received on Wed Sep 10 2003 - 11:34:00 BST