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PM3055 Phillips Scope fault

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sherb_j:
Hi All,
Nice to be on this forum.
I'm working on a PM3055 50MHz scope (got the manuals). Have replaced a burned out X2 cap and scope has come alive.
But ... all appears well except the A channel Y pos deflection doesn't work ( B channel is fine). If I apply a waveform(5v p to p) to the A input then
I can see the top of the wave peaks at bottom of screen when I drop the scope to the millivolt range, also if I kick in the Trig View then I see the whole wave form, centre screen but can't move it vertically. Any ideas as where to start looking would be much appreciated.
Got a couple of sheered pot spindles also. As they appear hard to come by, I've cut a slot in them so can adjust with a screwdriver. Look forward to hearing from you.
John.

tautech:
Just offer a simple but distinct waveform (square-wave, even probe cal output) to A input and follow the signal path with another scope.

Shock:
Reconnect and clean all the cables connections as well that's a common problem.
I would check the back of that control board and see if it has intermittent solder joints.

I couldn't find anything suitable as a pot replacements. They aren't rare at all, they are just sitting on other scopes.
I brought a damaged spare to repair the broken pots on mine just a couple of days ago.

sherb_j:
Ok, guys.
Many thanks for advice. 'Fraid I can't scope the scope as don't have access to another one but will look for dry joints etc.

Thanks again.

John.

tautech:
Often the manuals have DC test points on the schematic. Usually you have to set the scope in a specified way for the DC measurements. RTFM
You might strike it lucky, but when one owns an old scope you normally need another to fault find when it dies.

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