Re: Tek 485 - Intensity at Max, Cannot Adjust Down


wmactor
 

Thanks, Tom -

I read the thread that you referenced, and borrowed a high voltage meter . I'm seeing approximately +2700 volts on the cathode of the CRT, and the meter moves a very slight amount higher when measuring the grid. The intensity control has absolutely no effect on the grid voltage.


I see in your tests that the grid was driven -50V wrt the cathode, which pointed towards the bad CRT. My results seem to lead me back to the DC Restorer circuit.


I'll see if I can find replacement diodes and caps, and see if that resolves the issue.


Thanks again for your help!

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