[Philips210]

Hi.

Thanks for your replies and I appreciate your input.

The power supply voltages seem to be OK on the X-Y and Timebase boards. If the timebase is set to it's lowest speed then the dot pulsates. Increasing the setting likewise increases the flash rate so it would appear the timebase is working. The X control shifts the dot across the screen but not fully.

If the timebase is set to it's highest speed then a horizontal line appears. Reducing back the speed of the timebase also reduces the width of the horizontal line. Further reducing the speed results in just the dot on the LHS of the screen.

I applied the calibration waveform and it will show this if the timebase is set to max or near max.

I can trigger the timebase as per normal so that seems fine.

I am wondering if the problem lies in the X amplifier, although it's working to some degree it seems as if it's working with reduced sensitivity. It could still be the timebase though and it looks to be a tricky problem to solve.

It's all a little annoying as everything seems to be going wrong. I was using this scope to locate a difficult problem in a Korting 82515 TV pattern generator. That's all in pieces, circuit diagrams etc taking up the bench space so I'll have to clear that away from the bench to make room for the Hameg scope. New Year's resolution, "I must build a bigger, better workshop!"

I think I'll remove the X amplifier board for an inspection and cold checks on the transistors.

I could bing my Scopex scope into use but I suspect that needs a good service. All in all I have about 10 oscilloscopes but the Hameg was the only fully function instrument.

I'll try to report back in the coming days.

Regards
Symon.

EDIT: The X-Y mode switch seems to be functioning normally.