" Picked up a used IC-251A 2M all mode rig a few weeks ago. I left the
radio
on today and when I went back to it the evening, the display was blank and
by listening, it appeared that it could not be tuned. Turned rig off and
back on. No joy. Unplugged from wall outlet. Full joy! obviously the
rig
is partially powered up as long as it's plugged into the wall. Anybody
see
this problem before? If so, what was your fix. Don't really feel like
tearing into full blown troubleshooting. Guess I would start at the power
supply, but most likely trouble is in digital logic area somewhere, or
around CPU. Bummer. Hate when that happens...

While this probably does not have anything to do with your problem. The
Icom rigs of that series have a logic circuit that is running on a battery .
If the battery goes dead the rig will quit and you have to send it back to
Icom for a new battery and new programming. There is (was ?) someone that
makes a memory circuit that does not depend on the battery.