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