[Elecraft] KPA500

[David Olean]

I have a KPA 500 that is hardly ever used. I think I made less than ten 
contacts with it. As a result, I am not that familiar with it except 
that it worked great. I loaned it out to a friend and it came back 
broken. I am trying to figure out what happened. When I key the radio I 
see about 0.6 amps of idle current. TX Signals will pass thru OK on 
standby, but if I try transmitting into the amp, I see a high input 
VSWR  and the idle current stays constant at 0.6 amps. There is no 
output power.  It seems that maybe the input TR switch may be at fault. 
Question: What is the proper idle current for the FETS as displayed on 
the screen? If I had a schematic, I could dig into it, but not having 
that, I figured that I would ask a few questions to get me pointed in 
the right direction.  Can anyone help out?

Dave K1WHS