[Amps] Alpha 77DX problem

[K1SG at aol.com]

Wonder if anyone has seen this symptom before:
My amp was running fine this morning; I used it on 10 meters to work a  
couple of Middle East stations. 
I tried to put it into standby, so I could work a few Europeans at 100  
watts, but the Standby button wouldn't stay depressed. (If I wanted to stay  
depressed, all I'd have to do is watch the Red Sox melt down.)
I tried going back to the low power position, and got essentially no output 
 (maybe just feedthrough from the exciter, about 300 mA of plate current, 
30 mA  of grid current.  Any suggestions for where to start looking?
 
Thanks,
 
Steve
 
Steve  Gilbert
K1SG
K1SG at AOL.com
508-435-9133