Hello.
I have a Phillips PM 3232 oscilloscope – an old model now, of course, but I would like to rid it of an annoying fault.
The X-axis is not staying in place on the screen, but seems to be triggering at different times. The visible effect is that a waveform is smeared left and right to about 2mm left and right of the mean position. The calibration signal has a bright, well-focussed top, but the Y movements are diffuse and dimmer, although vertical. With the triggering set to the mains position (which isolates the trigger inputs from the Y amplifiers) the same effect happens – an AC sinewave is likewise smeared out in the X direction.
I have checked all supply voltages, both for voltage and ripple. These are in full accord with the service manual. I have also checked the transistors in the time-base unit, all to no avail.
Has anyone come across this fault before? Any help will be most welcome indeed!
Many thanks
Richard