Appreciate the replies, but nothing is wrong with any of the keys. The frequency dial needs to be replaced. It doesn't always react correctly when one wants to go up or down. Sometimes it does not respond at all. Other times, if I try to go up, it will instead adjust the frequency down, or vice versa.
My AOR 8200 MK3 had the exact problem. AOR USA ended up replacing entire CPU board as it would have taken too long to get the one part.
Edit - Perhaps a bad title led to some confusion. The turning dial that can be used to go up or down in frequencies needs to be replaced.
Ty