[R-390] Suggestion please

[K3PID]

My R390 went dead on 80 meters.  Before taking it out of the cabinet and starting on it I did a little external troubleshooting.  Here are my observations:

1. All “Megacycle” positions except 3 seem OK.
2. At a setting of 3.500 MHz the antenna trimmer has NO EFFECT on the carrier level meter reading which is constant at about 60 dB.
3. At a setting of 3.500 MHz the calibration signal can not be heard at all.
4. At a setting of 3.500 MHz a very strong signal from a signal generator loosely coupled to the antenna input can be heard.

HOWEVER

5. At a setting of 2.500 MHz which uses the same transformer T203,  all is normal with both the antenna trimmer and the calibration signal.

Any suggestions will be welcome!
73 K3PID Ron