I have an old 1991 14" TRL VGA monitor which I would like to fix.

It was working until it started making a horrible noise. I took the cover
off and could see the flyback transformer flashing over to the chassis. I
cleaned out the burn marks and covered them with several layers of epoxy
glue.

When I turned it on the monitor worked for about a minute and then it
started arcing on the PCB that plugs onto the tube. There seems to be a
spark gap on the connector itself.

Is there something wrong with the flyback transformer - voltage too high?

Any ideas?

Thanks
Paul

Paul writes:

I have an old 1991 14" TRL VGA monitor which I would like to fix.

It was working until it started making a horrible noise. I took the cover
off and could see the flyback transformer flashing over to the chassis. I
cleaned out the burn marks and covered them with several layers of epoxy
glue.

When I turned it on the monitor worked for about a minute and then it
started arcing on the PCB that plugs onto the tube. There seems to be a
spark gap on the connector itself.

Or more likely an internal short. The screen and/or focus voltage on
the CRT PCB is too high which is why the spark gap is arcing.

Even if the original problem was excessive voltage caused by something
other than the flyback, the flyback is now damaged and would need to be
replaced. It is probably impossible to find one now.

--- sam