[Kenwood] TS-680-S Partially dead.

[Albert Morris]

Hello all.

I have a TS-680-S which is dead above 21.5MHz.  By that I mean it goes
to an "Unlock" condition when I tune above 21.5MHz.  It was working
until I attempted to tune the AT-250 on 10 meters the other day and the
rig immediately appeared to go dead.  I did a processor reset which
resulted in the CW readout returning and giving me the "Unlock" in CW.
Looking at the service manual I do see that there is logic in the
TS-140/680 to switch in VCOs for those ranges and I think that the gates
are ganged on both of those if I am reading the schematic correctly
(which makes sense as it does not work on 6M either and the additional
gate and VCO is for 6). =20

My question is - Has anyone encountered this before and/or does anyone
have a "highly" suspected component that would account for this.

Thanks in Advance - 73 Al WB8FEQ