[R-390] R-390A Tuning issue

[wb5uom at hughes.net]

If this issue has been covered I missed it, and I am betting more than one
of you guys (gals) know the answer:

My 390A has been doing perfectly fine. I had an antenna issue and was too
lazy to go out and fix it until this weekend so I had not been listening to
the Receiver for 2 or 3 weeks    -although it is ON all the time.

What I find today is that it appears the lower 500Khz in each Mhz range is
dead. (I tried several different Mhz settings all with same response).
And yes above and below 8Mhz.

If I tune to say 11.820 it receives perfectly, tune down to 11.500 and its
dead as a doornail
The same for say 8.920 and 8.500 as so on.

Hints anyone?

Thanks in advance

David / WB5UOM