[ETO_Alpha] Problem with 91b

[Ronald Sekkel]

Hello All !

After several years of good work, I'm having some problems with my Alpha 
91B amp.

As it would be very impossible to send it for repair, I was wondering is 
someone could help me understand what my be happening.

If I disconnect the high voltage plug from the transformer it turns on ok, 
and I can see step start relay K2 working ok, and all other voltages seems 
to be ok.

But if I connect the HV plug, R1(560ohms/2w) and D1 (1N4007) from the AC 
MAINS board are burned as soon as I try to turn it on.  This happens even 
if the HV output is disconnected.
All Power supply diodes seems to be ok.

I just can't see the connection between the HV and R1/D1.

Any help is welcome. Thanks in advance.


Ronald J. Sekkel - PY2FUS
py2fus at integral.com.br
Grid locator: GG66pt