Analogue monitor board repair

Peter Coghlan cctalk at
Mon Oct 31 16:22:12 CDT 2016

> Before I replaced the failed potentiometer (new one seen top left) the
> display looked like its horizonal hold had gone so I reasoned that's what
> the pot controlled. I can *nearly* get a steady picture but the brightness
> is out as well, despite there being working pots for that and contrast. The
> brightness seemed more constant before I replaced the radial cap with the
> PET one which is why I wondered if the choice was wrong.

Did you measure the resistance of the track on the old potentiometer
and use something with a similar value for the replacement?

Is it possible that you misread or misinterpreted the value of the capacitor
that you replaced? You could try putting the old one back and seeing if there
is an improvement.

What is PET in this context? I am assuming it is nothing to do with Commodore.

Can you take a photograph of what you are seeing on the screen?

Peter Coghlan.

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