[Amps] Help with TL922A PS trouble

[Gudguyham at aol.com]

Hello, I would try disconnecting the HV AC from the transformer to the PS 
board, so that the only thing connected to the line voltage is the filament 
transformer, and the HV transformer. Protect the ends of the wires from the power 
transformer.  Turn the unit on see what happens, switch to SSB, see what 
happens, if OK, then problem in PS somewhere.  If you still blow a fuse at this 
point, your problem is with the line voltage to the transformer, it could be that 
the SSB tap has a short or perhaps the cw/ssb switch is shorting the primaries 
together in the ssb mode.  This can be checked with all wires removed, and 
check switch with ohm meter.  If all checks OK, then you reconnect the HV AC to 
the PS board, and it blows a fuse then, if may be a leaky cap to ground if you 
have checked all else (diodes, etc).  You may want to disconnect the HV and 
B- from the rest of the circuit also to see if perhaps there is a problem AFTER 
the power supply as well.  Foe example, a shorted blocking cap will cause the 
mains to blew right away.  Key is to "isolate"!!  Good Luck 73 Louie