[Yaesu] FT-101E tramsmit problem

[W1UK]

Restoring an FT-101E that is exhibiting an unusual problem.

The power output is intermittent occasionally when keyed.  At times it is
full output, and then when keyed again power drops to only a few watts or
nothing.  Cycle the transmitter again and the power is back to full output.

I have cleaned the contacts of both relays and tested them outside the
radio.  Both seem to work properly.

Any suggestions on what might be wrong?