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546 Trace off screen

ethanfg99@...
 

Hey all,

I just acquired a 546 and tested it out for a couple hours. After shutting it off and turning it back on later, the trace disappeared as I was using it. It wasn’t gradual, the trace instantly disappeared and the scope says that it’s off the screen to the right. Turning if off for a while and then back on or changing any settings has no effect. I was having issues with the power on delay relay, and narrowed it down to bad contacts on the relay. After cleaning them the scope powers on normally but has this issue. Could this be from lack of power to a portion of the scope? I know the relay switches many different circuits - maybe it’s not switching on the power for the horizontal amp?

Any input would be greatly appreciated.

Steph L
 

Your thinking is logical.

The next step would be compare actual voltages on the 546 to those given on Power Supply schematic sheet 1 of Service Manual and the Horizontal Amp elsewhere.

You can begin here, if not already known.

http://w140.com/tekwiki/wiki/Main_Page

Steph.

ethanfg99@...
 

Steph,

After checking voltages and combing over the scope, I found that one of the horizontal amp outputs to the crt circuit that go through the thick shielded cable ( not sure what it’s called) was shorted to ground. Fixing this has returned the trace to normal.