Hameg HM205-2 asymmetrica display.....

[ecca]

Hi all from a newbie......
I bought a Hameg HM205-2 oscilloscope this morning at a car boot for the princely sum of £3.
It's cleaned up OK and miraculously it all appears to work OK except that the display is asymmetrical, one side different to the other horizontally.
I've downloaded the manual but there's no solution there that I can see.
Any ideas ?
Here's a picture......



Cheers,
Eric Thacker (UK)

 

[BradtheRad]

Your beam starts out fast, but then slows down during its sweep toward the right. This is a fault in the sweep waveform.

The sweep is a sawtooth oscillator. The sweep waveform should be linear. You probably have a component which no longer has linear gain characteristics.

The scope has internal calibration adjustments, for sweep speed, and sweep length. Can you locate these? There is also horizontal position on the front panel. By playing with these various adjustments, it may help you to diagnose the correct section.

 

[ecca]

Thanks for that.
I've located a preset VR3101 on the TB board that I will adjust.