Info needed on HP 2161A power supply.

Hello list readers.. Does anyone have schematics for a Hewlett Packard 2161A power supply? This is the power supply for the HP 2115 computers, and I beleive that it was also used for older HP I/O extenders as well. I'm having a problem with one of these power supplies, it simply will not turn on. All internal fuses have been checked, and a single bad fuse was found. Replacing this fuse had no effect and the replacement fuse does not blow. The back of this power supply has a connector that suggests it may have some sort of power-control function (like for I/O expander applications where it is turned on by an external signal). But the 2115 computer simply has 2 massive power cables, and nothing to connect to this additional smaller connector. A casual inspection of the 2161A's interior shows no clear power control relay (this is a high current linear power supply). Lacking schematics, its not easy to figure out what is supposed to be going on inside. Lastly, when attached to the 2115 computer, applying AC power to the supply (with all power switches off) causes the cooling fans in the 2115 to start running. This seems odd. I would expect the cooling fans to only start once the power switch was turned on. Turning on the power switch has no noticiable effect. I have verified continiuity from the power switch (on the 2115) through the cables into the 2161A supply, but I have not followed it internally through the 2161A's maze of wiring.