CRT monitor problem: yellow skews

[Yousuf Khan]

Now my old 17" monitor is starting to act up. It does this only after
coming out of standby mode, but for about 5 seconds after coming out of
standby, the yellow pixels are skewed off to the right from the rest of
pixels, then they synchronize eventually. It's almost like seeing a
yellow ghost of the image. What causes this? Admittedly the monitor is
getting old (ca. 1996), but it only started doing this in the last few
months.

Yousuf Khan

 

[Bob Myers]

Now my old 17" monitor is starting to act up. It does this only after
coming out of standby mode, but for about 5 seconds after coming out of
standby, the yellow pixels are skewed off to the right from the rest of
pixels, then they synchronize eventually. It's almost like seeing a
yellow ghost of the image. What causes this? Admittedly the monitor is
getting old (ca. 1996), but it only started doing this in the last few
months.

It's not actually yellow that's off; yellow is a mix of red and green,
so what you're actually seeing is a horizontal misconvergence error
of the blue. It's not unusual for the convergence correction
circuits to require a bit of warm-up time to reach proper operation.
You see this coming out of "standby" mode most likely because
in your monitor's case, "standby" leaves enough current through
the CRT heater such that the image shows up before the
convergence circuits are warmed up.

That it has shown up only in the last few months does say that
something getting older (or going a bit out of adjustment) is
likely the cause, but it's no cause for alarm just yet as long
as it DOES go away in a reasonably short period. Or it might
be that you simply haven't noticed the condition before, and
it's perfectly normal for this monitor.


Bob M.

 

[Yousuf Khan]

It's not actually yellow that's off; yellow is a mix of red and green,
so what you're actually seeing is a horizontal misconvergence error
of the blue. It's not unusual for the convergence correction
circuits to require a bit of warm-up time to reach proper operation.

Okay, yes, there is no yellow in RGB, so it must be the B that's
diverging here.

Yousuf Khan