[comp.sys.ibm.pc] What's wrong with IBM EGA

izumi@violet.berkeley.edu (Izumi Ohzawa) (07/20/88)

Help!
We have two IBM EGD or EGA monitors, both of which are in the
process of getting burned out.  It's not the phospher or
gun getting low emission, but the vertical scan circuitry.

Simptom is initially a somewhat expanded vertical scan amplitude.
This expansion goes away after 10-15 minutes after power up.
But this expansion occurs immediately after power up every time now.

After this goes on for a few months, vertical scan becomes jittery
immediately after power on.  Again this seems to go away after
some time of operation (15 min), but not completely.

Now the vertical scan amplitude does not shrink to normal size,
and attempt to reduce V scan amplitude makes V scan jittery.
This 'jitteriness' is not due to the loss of V synchronization.
I know how loss of V or H sync looks like.

Does anybody have a similar experience?
Do you know what component is going bad?

These monitors are like 2-3 years old, have been used about 10 hrs
daily.  They shouldn't go bad in this manner.

The fact that it is showing up on both of our monitors makes me
wonder if EGA monitor's design or a certain component was flawed.

Any ideas?

Izumi Ohzawa
izumi@violet.berkeley.edu