[Amps] Alpha 76A inop of all bands except 15M

[nu7j at hotmail.com (Tom Sykes)]

My Alpha 76A quit working the other day.  When I key it up and apply input 
power, the forward and reflected power output from the amp is zero.   (As 
measured by the on-board power meter, and confirmed by my external power 
meter.)  

That condition exists on all bands except 15 meters, which is operating 
normally.

Any ideas and troubleshooting tips would be greatly appreciated!

Thanks and 73,

Tom, NU7J
nu7j at arrl dot net