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Eremita Analogico Eremita Analogico is offline
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Default Help for hard repair attempt

Il 13/06/2018 01:08, ha scritto:
"...output of the log amplifier is being

corrupted... possibly by a regular variation in voltage. If the
Advantest uses a switched-mode power supply to create its analog
supplies, there might be a fault in the supply which is causing it to
dither between two different voltages."

If you are right it may be as simple as a filters. I have a tendency to scope the supplies first unless indications are clear that that is not the problem

What we do not see with the still is whether those square type waves are stationary or they move, roll across the display. If they do move and they change direction or velocity with line voltage the answer is right there.

That's the simple answer, if that ain't it then that could be a problem.



Hi, preliminary tests was done some times ago, and if I remember right,
the various supply lines do not have ripples. When I got time, I will
try again to verify supplies.
The tooths are stationary over the waveform.