Zorg K

Ok, unit is working again.&#160;<br> <br> I ordered replacement reed relays, and measuring the new units against what was in the board, I determined they were likely not the issue.&#160;<br> <br> My unit came with the inputs in the rear, which means there are two very long runs of something akin to rg-174 coax from the very front edge of the main board all the way to the rear of the unit, running under the main board. By chance, while probing the 5V supply seeing if I could find the short by looking at milliohm differences between the chasis and areas of the trace, I happened to turn the device over and nudge one of these coax lines and the resistance between 5V and chasis went from 0.25 to ~700 ohms.&#160;<br> <br> Upon close inspection, it looks like an IC pin on the 5V trace that loops around near the front of the device had pierced the non-conductive cover of the coax and was touching the shielding, which is of course grounded. I don't know why that didn't blow the fuse, but there you have it. After that, the unit powered on and booted normally.<br> &#160;

Update: I've replaced the tantalum capacitors on the main board and none of them have looked bad on the LCR meter, so I imagine the problem is elsewhere. After re-jumpering the voltage supply traces, the +5 is still being pulled almost to 0V, so onward I hunt for another shorted part.

I have had this Keithley 776/R for a few years, but it stopped working on me the other day, after re-arranging my workspace. This has the TCXO and 2.4GHz options. 
Any copies of the manual I've found online have essentially unreadable schematics. I'm looking for either a high quality digital copy or a physical copy of the manual. 

As far as the problem itself:
* no display, beep, or any action when turning the power on from the front panel switch
* I noticed the +/-5V regulators were very hot
* I've verified there is power running into and out of the mechanical front panel switch when it is enabled
* I've de-soldered the +12V, -12V, +5V, -5V jumpers on the bottom of the main board, and validated that the two stages of the power supply are working in isolation: first the +/-12V, then the +/-5V, measuring within spec on output side of jumpers. No excessive heat without the 5V jumpers closed.
* While poking around, before re-soldering the +/-5V jumpers, I noticed that the +5 far side of the jumper has direct continuity to ground. All of the others have a few kOhms at least. Perhaps a capacitor went bad, or a relay is stuck? I've had to replace a couple of the Tantalums that had randomly popped in the past, but none of the remaining are showing any outward signs of failure.

Any suggestions welcome! Thanks.