Mouse Pissed! Need power supply help

[Allison]

>
>Subject: Mouse Pissed! Need power supply help
>   From: Charles <charlesmorris at direcway.com>
>   Date: Wed, 23 Nov 2005 10:51:33 -0600
>     To: cctalk at classiccmp.org
>
>I've found the reason why my PDP-11 power supply (H7861) is not
>putting out POK and DCOK signals. One of the small daughterboards
>which appears to provide the level checks and timers (marked
>Digital Type 1 SG-1 5015047B  5415048) has been badly mouse-pissed
>and rusted. (Previous owner stored it in the carport).
>
>There is enough corrosion that the leads of two diodes and two
>film resistors have been rusted right through and broke off during
>gentle toothbrush cleaning, and several others don't look good. I
>suspect the board would be better replaced than patched.
>Unfortunately the H780 schematic does not match closely (they use
>74123's while this one uses 555's, for example) so it'll be hard
>to figure out the missing or unreadable parts anyway!
>
>Does anyone have a spare board from a "parts" power supply?
>Or at least a schematic?
>
>thanks
>Charles

Your best bet is to scrounge a power supply as they can be had.

The H786 and H7861 are interchangeable, not the same circuit but
fit the same form factor.  A H780 can be used but it's not a 
mechanical fit.


Allison