Pioneer621
- Aug 3, 2010
- 13
- Joined
- Aug 3, 2010
- Messages
- 13
Hello, hoping for a little advice on an oscilloscope problem I have.
It powers on, I can get a trace on the screen & get it to lock on waveforms, but there is a small portion of the screen where the waveform is not displayed correctly. I’ll show some pictures of the waveforms below.
I have measured all the power supply voltages my meter will allow & they measure ok. I found a leaking capacitor on the main sweep board, but that did not solve the issue. At this point I don’t really know where the problems may be. I think it may be a sweep problem of some sort as if it set a slow sweep, say 2 SEC, it sweeps normal until it hits the mentioned problem area then greatly slows down for almost 2 divisions until it resets, then starts over.
After sitting for a while & turned on the trace is deflected below the screen and the position control cannot get it up, the beam find shows it. After several minutes it comes up though. Maybe more bad capacitors?
Also, from 10 uSEC down the trace does not sweep fully across all horizontal divisions, but from 5 uSEC up it does.
Thank you for any help on this, it is greatly appreciated.
Here is the service manual PDF for reference: http://cp.literature.agilent.com/litweb/pdf/01741-90911.pdf
Here are some pictures of the waveforms; maybe this will indicate where the problem may be: (sorry the quality is not that great)
20khz input; time/div 50 uSEC:
20khz input; time/div 20 uSEC:
20khz input; time/div 10 uSEC:
20khz input; time/div 5 uSEC:
Here it is with an HF signal; time/div 2 uSEC:
Again but set at 1 uSEC:
It powers on, I can get a trace on the screen & get it to lock on waveforms, but there is a small portion of the screen where the waveform is not displayed correctly. I’ll show some pictures of the waveforms below.
I have measured all the power supply voltages my meter will allow & they measure ok. I found a leaking capacitor on the main sweep board, but that did not solve the issue. At this point I don’t really know where the problems may be. I think it may be a sweep problem of some sort as if it set a slow sweep, say 2 SEC, it sweeps normal until it hits the mentioned problem area then greatly slows down for almost 2 divisions until it resets, then starts over.
After sitting for a while & turned on the trace is deflected below the screen and the position control cannot get it up, the beam find shows it. After several minutes it comes up though. Maybe more bad capacitors?
Also, from 10 uSEC down the trace does not sweep fully across all horizontal divisions, but from 5 uSEC up it does.
Thank you for any help on this, it is greatly appreciated.
Here is the service manual PDF for reference: http://cp.literature.agilent.com/litweb/pdf/01741-90911.pdf
Here are some pictures of the waveforms; maybe this will indicate where the problem may be: (sorry the quality is not that great)
20khz input; time/div 50 uSEC:
20khz input; time/div 20 uSEC:
20khz input; time/div 10 uSEC:
20khz input; time/div 5 uSEC:
Here it is with an HF signal; time/div 2 uSEC:
Again but set at 1 uSEC: