Philips PM3323 Oscilloscope

[Greg]

I have a Philips PM3323 digital oscilloscope which has not been used for
some time. It has developed a problem where both A and B channels have
become very noisy such that the noise on the display is now larger than the
wanted signal - making the scope unusable. Timebase and y-axis functions all
appear to be still working OK.
Can anybody tell me whether this fault is likely to be economically
repairable?

Many Thanks,
Greg

 

[klasspappa[remove]]

Is it possible to clean the front switch?

 

[pjohn23]

It's most likely the 10 uf @ 16v aluminum bypass caps. They dry out.
You'll probably have to replace them all.
Phil J

 

[Greg]

The front panel switches control the voltage range indicated on the display
correctly, but don't seem to affect the magnitude of the noise on the trace.
I suspect the problem may be on the A to D converter card.