[TenTec] Centurion 422 amp keying issues

[wa8wzg at wa8wzg.net]

To All..
My 422 amp has developed a keying issue..when it is keyed in either qsk 
or ptt mode. it wont un-key until I go to standby , put it back in 
operate and just short the ptt jack momentarily to ground,it keys 
up..but same issue,,I have to go to standby to un-key,,
Before I dig too deep into the 81542 QSK board,, has anyone had this 
issue,,
trying to save some troubleshooting time,,
Thanks for your help..
Tom
N7GP
ex WA8WZG