I have two monitors doing exactly that over a 10-30 minute period. What
happens is the Screen and Focus voltage are increasing beyond their normal
value. Even adjusting the EHT transformer Screen and Focus down doesn't
solve the problem completely. You might be able to get the Screen voltage
about right to give the right brightness, but the Focus will be out of range
causing a fuzzy screen. You could try that if you take appropriate
I believe the fault is in the EHT transformer itself, but have yet to proove
it. I have one good monitor that I hope to swap parts with to proove it, but
havn't got time at the moment. I have replaced lots of components in mine
that were a bit out or damaged, but the fault stayed the same.
I have not found a source of those EHT transformers anywhere. As far as I
can tell they are not available. I have tried Mitsubishi and Apple in
Australia without success.
> Anyone know what would cause a IIgs RGB monitor to slowly increase in
> brightness\contrast? What components may be bad?
> When it's first turned on the display looks normal but as it warms up the
> brightness and contrast slowly increase to the point where it's too
> I even have the brightness and contrast dialed all the way down.