I was using my t-912 for about an hour, then I walked away and came
back, there was no trace anymore. The crt filament lights up fine, and
I can see the trace briefly appear then I turn off the power switch,
so for some reason it is being blanked, I guess. The beam finder does
not help finding the beam.
Not having a schematic I don't know what voltages to check for at the
various test points.
If anyone has any suggestions, or a schematic, please let me know.