[TenTec] OMNI-VI problem

[K8mp at aol.com]

Anyone seen an OMNI-VI do this?
 
Symptoms:
The rig appears to be stuck on the same QRG all the time. The  freq display 
changes when you crank the tuning knob, but it's not actually  changing the 
RX freq and I suspect it's the same with the TX freq.   Changing the RIT 
has no effect either.
 
If I change bands, the RX freq does change. For example, if I switch  to 
160, I hear what I believe is an AM broadcast station. However,  the tuning 
knob still has no effect. I'd like to be able to ID  that station, to find out 
its freq.  That might give me a hint as to what  has failed. Its audio is 
unintelligible because I can't tune to  zero-beat.
 
By the way, 160 is the only band that I can hear a signal. I suspect the  
other bands must be stuck on obscure frequencies.
 
Master reset didn't help.
 
Thanks, Joe, K8MP