Tektronix TDS3032

[BrianH]

Hi everyone,

I have a slight problem with my Tektronix TDS3032 which I'm hoping someone here may have some information on. When I power the unit on, it passes all self checks but when I try to display a waveform on channel 1, I find that the trace is displaced by a couple of volts - exactly as if it's sitting on a D.C. level. This happens even when there is no scope probe connected, and when the unit is set in A.C. coupling mode. The waveform does otherwise display fine with no distortion.
Because of this problem, on most of the vertical scales no signals will display at all. Instead the scope complains that the waveform is clipping - presumably because the waveform has been shifted way off the screen. The only ranges that the scope will display a waveform on are 1V/div and above, and then I can observe the displacement problem.

Channel 2 works normally.

Has anyone else experienced this? Or, do you have servicing information for the TDS3032 which may be useful to me? I do actually have two scopes (one old horrible one and the TDS3032) so I could use my other scope to diagnose this one

Thanks for any advice

Brian