Troubleshooting/repair Hameg 1500 scope

Thread Starter

Crazy_BJT

Joined Mar 14, 2020
10
Hi there to you all, I need some help with a troubleshooting/ repair.
I have an analog/digital oscilloscope Hameg HM1500, it has some RTC problem, it presents a partial sweep.
I think is the horizontal circuit, that's either missing a voltage or there is some faulty component.
The only problem is that I can't find the schematic for this scope, only for the model HM1500-2, but it's completely different, and it's complex to do troubleshooting without it.
If someone has this schematic, I'd appreciate your help.
Thank you to everyone:)
 

Thread Starter

Crazy_BJT

Joined Mar 14, 2020
10

AlbertHall

Joined Jun 4, 2014
9,650
You have a 'partial sweep'? Does that mean that the sweep is not as wide as the screen?
If you move the X-Shift will the ends of the sweep reach the edges of the screen?
Does the width change with the tims/div setting?
Does everything else seem to work properly?
 

Thread Starter

Crazy_BJT

Joined Mar 14, 2020
10
You have a 'partial sweep'? Does that mean that the sweep is not as wide as the screen?
If you move the X-Shift will the ends of the sweep reach the edges of the screen?
Does the width change with the tims/div setting?
Does everything else seem to work properly?
Everything else seems to work properly, even the time/div settings, the partial sweep appears to be from the center of the screen to the right, I can move the beam only in that space vertically and horizontally.
 

AlbertHall

Joined Jun 4, 2014
9,650
If you display a waveform does it get squashed at the centre or does it just not shift past that point?
Does it look as if there is more sweep off the right side of the screen?
 

Thread Starter

Crazy_BJT

Joined Mar 14, 2020
10
If you display a waveform does it get squashed at the centre or does it just not shift past that point?
Does it look as if there is more sweep off the right side of the screen?
Nope, the waveform it's displayed like is smaller than usual, il like the screen is reduced in a space between the center and the right side of the normal screen.
 

AlbertHall

Joined Jun 4, 2014
9,650
Sorry I missed out a word - 'half'.
I would expect the period as displayed on the screen to be about half the actual signal period. So 1kHz would show with an apparent period of 0.5ms.
If this is so then the timebase is probably OK and the problem is with the X-amplifier or X-output circuitry.
As this circuit will most likely be differential then probably one side of this is defunct.
 

Thread Starter

Crazy_BJT

Joined Mar 14, 2020
10
Sorry I missed out a word - 'half'.
I would expect the period as displayed on the screen to be about half the actual signal period. So 1kHz would show with an apparent period of 0.5ms.
If this is so then the timebase is probably OK and the problem is with the X-amplifier or X-output circuitry.
As this circuit will most likely be differential then probably one side of this is defunct.
That's what I think too, it could be a faulty component from the power supply to that part of the board, the only problem is I need the schematic to try and see where exactly is the problem
 

Thread Starter

Crazy_BJT

Joined Mar 14, 2020
10
I have a guess.
There will be two transistors driving the two X-deflection plates. Check them first.
There are two boards that seem to be driving the horizontal part of the CRT, but it's really difficult to understand which is doing what, considering is a hybrid oscilloscope.
 
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