Re: 7904 - Very Dim Trace

 

It has to be more than a z-axis amplifier problem because Jim measured
the 2950 volt cathode voltage at 3250 volts. I wonder if that by
itself would be enough to cause the problem.

Alternatively, could the measurement be wrong? Jim, can you verify
proper operation of the probe you used to make that measurement?

On Mon, 8 Feb 2016 10:24:59 +0100, you wrote:

*If* the X / Y deflection works as before, so calibrated time base steps
are still correct and calibrated vert amp steps, too, then you are
likely looking at a Z axis issue.

I'd recommend to check if the Z axis amplifier output is as expected. If
it is not, check the amplifier, if the amp is okay, check the Z axis logic.
If the amp output is okay, replace all HV caps and all diodes in the Z
axis DC restorer circuit.

Cheers, Marian

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