Re: 7834 High Voltage Board

Craig Sawyers <c.sawyers@...>
 

What you seem to be saying is that the main power supply works fine when the coax inputs to T2010 are
not connected, but when you connect them the main supply goes into tick mode?

Is that correct?

Craig

-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of ef804s tubes
Sent: 15 October 2018 15:55
To: TekScopes@groups.io
Subject: [TekScopes] 7834 High Voltage Board

Hi,

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,

Fred

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