Keithley 2700 - Repair

 I couldn't resist. Found this puppy faulty on the eBay.

It doesn't turn on. Even consume zero current from the mains.

For a quick look: the fuse is intact. Tested the AC connections from the mains transformer. Nothing come out. Ok, so either the mains transformer or the mains connector module (connector, voltage selector, mains switch) faulty.

Checked the Mains connector module. Unfortunately the available service manual is useless. So with the mains module, done some reverse engineering.

Here is the transformer's connection:

Measuring the transformer I found out, that the 100V winding is demaged.

So, I connected the 100V - 220V cables (blue and gray) to my variac, and set the voltage to 120V.

Here are the results:

For the first sight, it looks like, it has no other issue than the faulty mains transformer. Now I need to find a replacement unit, or somebody, who is able to wind a new one for me.