I posted a long time ago about my trouble with the scope and in the last few days i tried to give it another go.
i attached the schematic and the board layouts, and i have some questions.
http://www.filehost.ro/3172105588/BM566a_pdf/1. on the last page, down left, the push pull output for the intensity control doesn't work (near U212) there is no were in the manual anything about how much it should be, but i traced a little and it seems to be the intensity. The 2n3495 has been replaced with a mpsa92, and the npn transistor gets burnt whatever i do. So i left it out, and the illumination is at it's peak. Can you suggest a transistor that would work? MPSA42 doesn't unfortunately, and R175, R176 and R178 get burnt.
2. The scope is seriously out of calibration. On most scales (0.1V/div and lower) a 4v signal fills about 3 divisions, and on a 1v/div it's like 1-2mm tall. At most. Can this be a deflection problem, aka it doesn't have enough voltage to show it all? Also it has so much ripple on the deflection it looks line a sine wave superimposed over the square one. It cannot be brought into calibration by any knob. It's like i need a 10X amplifier.
3. When the scope displays the image it looks like a part of it is squished to the left, where the trace starts. This should be a deflection issue, right? But even if i move it left or right it's the same. A part of the image is squished there.
It has a lot of other problems but those are bad.
I have checked the power supply and it's spot on. The electrolitycs are older than Dave but they work a treat. The voltages going in all the boards are ok. (+-2%). I don't have the courage to probe the HV stuff, but it seems ok. I have an image.
If i was not too suggestive with my description of the issues please ask for more info.
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