7834 High Voltage Board

ef804s tubes


recently I acquired a non-functional 7834. After finding a bad tantalum on
the +15V on the readout board and an open zener in the -50V supply,
I was very happy that the supply came up and there was no obvious short in
the high voltage section. But, no high voltage was present. After opening
the cage, I saw, somebody had disconnected the two coax connectors
supplying the AC voltage. After reconnecting, the power supply did not come
up. I disconnected the secondaries of the high voltage 25Khz transformer
but the symptom remained, so to me it looks like a shorted transformer.
Therefore, I need a new high voltage board or transformer. If you agree
with my diagnosis, could you please help to locate a high voltage board.

Best regards,


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