Batboard

Found the problem today with the COM120B, was getting rec level error, distortion meter error. Swapped the baseband and the receive boards. Replaced the rtc Dallas IC. Still had the problem. Tried a cal, same problem. Then checked the functions to find the generator output was 30db low. I thought it may be the attenuator, so I checked the signal coming from the generator module. Not sure what is in that module, some switching for the aux/tr port?

Gave it a tap with the end of a screwdriver and the output returned to normal.
All was well, no more errors. More taps and it has not failed (yet)

So I am thinking the self test does a RF loopback in duplex mode and if the output is low you get errors, misleading for sure. Lesson Learned.