Quadtech 7400 LCR meter external bias fail

[Electrole]

Hi, I have a Quadtech 7400 LCR meter which works very well, but with one exception: There's no connection from the external bias voltage input to the device under test. The voltage ends at the two pins where the external bias voltage enters the main board. The bias fuse on the back panel is OK. The internal bias function is OK (though the voltage is 1.85 V rather than the specified 2 V). I really suspect some relay malfunction, but before dismantling an otherwise well functioning piece of gear, I wonder if anybody should have the schematics for the 7400 available. It seems that there's nothing available out there on the 'net. A service manual with schematics would be just wonderful...  If not, I think I will just have to take a closer look at a few relays...
Best regards

[coromonadalix]

Try asking the company  if a service manual is available, or sign an non disclosure agreement ??