[Drake] TR7 Shutting down

[Wa1cvn at aol.com]

Early PS-7 power supplies had an RF overload problem with the current sense  
circuit which would turn off the power supply.  Please check the serial  
number, if it is below 1500 I would suspect the RF overload problem.  Try  changing 
power supplies or monitor the 12v line and see if the voltage goes away  when 
the TR-7 shut down then the power supply is at fault.
 
Second possibility, bad pass transistors which can't handle  the current 
requirements above the 40 watts level.
 
good luck
Dave