LF: Microvax 3100 power supply technical information.

Hi Guys, I have a "VAXserver 3100" which afaik is the same hardware as a Microvax 3100. This unit has a bad power supply. The power supply is labled: MODEL H7822-00 Anyone have schematics or other technical information? In case anyone has run into this before - the symptoms: This supply appears to be two "mostly separate" supplies in one box. Both boards have connection to AC power. One board generates +5, -5, +12 and -12v, which is the sent via jumper wires to the second board - There it appears to be monitored by a "power good" circuit, and passes directly to the connector for the VAX mainboard, and one of the two disk drive power connectors. All of these rails look good. The second supply generates +5 and +12v which is applied only to the second disk drive power connector. This supply constantly starts and stops - with or without a load. I can see the output voltages coming on, then going off over and over. Since this supply drives only the second disk drive power connector, the system shoud come up, however it does not - I believe the reason for this is that the power monitor is either holding the system in reset, or providing a "bad power" indication which otherwise halts the system because the second drive supply voltages are not stable. The connector to the VAX mainboard looks like this (viewing end of power supply cable) -12 +5 Gnd +12 Gnd +5 [Key ] Gnd Gnd [Tab ] +5 Gnd [Here] +5 -5 ?1 ?2 The ?1 and ?2 signals appeare to be control signals. All power rails look good. With a supply borrowed extra drive connector/supply, but same main pinout), I see 4+ volts on ?2 and some low but non-zero voltage on ?1 - with the bad supply, both ?1 and ?2 are at 0v. Can anyone tell me the names and description of function for the ?1 and ?2 signals - I'd like to know exactly what these are supposed to do as the supply comes up. Any other technical information and/or ideas would be very much appreciated. Regards, Dave -- dave06a (at) Dave Dunfield dunfield (dot) Firmware development services & tools: www.dunfield.com com Collector of vintage computing equipment: http://www.classiccmp.org/dunfield/index.html