Radius PrecisionView 21 Monitor - Red convergence problem

[glenn]

Blue and Green are perfect. No ghosting or convergence issues

Red Horizontal lines are perfect. No Vertical ghosting or distortion.

Red Vertical lines have perfect vertical line but faded red ghosting to
right side. Red vertical lines are clearly visible. Red ghosting is
approximately 4-5 times wider than original line. Fading goes to black
eventually. Again, no vertical ghosting in the Red Horizontal lines.

Convergence screen patterns show this ghosting effect is not correctable
with on-screen controls.

I cannot find a service manual for this monitor.

sci.electronics.repair FAQ has good info, but suggests this type of repair
should be done with service manual.

No shock, lightning or EMP bursts have occured. This just started
happening.

Any TV/Monitor techs out there can tell me what to turn and where?

Thanks,
Glenn

 

[John Gill]

Glenn:
If your convergence has been good in the past, I would check the capacitors
on the CRT neck board, especially those near the video amp IC.
They are usually about 1Uf at 50 to 160 volts. As they age, they develop
high internal resistance and cause the ghosting effect. I use an ESR
meter to check these caps.
If you do not have an ESR meter, you may just want to change all those
near the video amp IC. They are inexpensive.
John

 

[glenn]

John

Thanks. I don't have an ESR meter, I may have to remedy that as well.

And yes, the convergence just went, no warning.

Last night I left the monitor on with the screensaver running, when I
checked it this morning the ghosting was gone, then I get home this
afternoon it's back. I didn't think a cap could do that. I'll check what's
there though. Problem is, it's surface mount components at the neck board.
Except for the actual multi-pin socket board that has maybe 5-8 normal size
components, I know I saw a large orange cap and a fairly good sized fuseable
resistor.

I'm currently using the monitor. The red tinge to everything caused by the
horizontal ghosting is annoying, but at least I can ask for help.

Again, thanks for your time and your answer.
Glenn

"John Gill" <jdgill@juno.com> wrote in message
news:71016e83.0404290619.1fef127f@posting.google.com...

Glenn:
If your convergence has been good in the past, I would check the
capacitors
on the CRT neck board, especially those near the video amp IC.
They are usually about 1Uf at 50 to 160 volts. As they age, they develop
high internal resistance and cause the ghosting effect. I use an ESR
meter to check these caps.
If you do not have an ESR meter, you may just want to change all those
near the video amp IC. They are inexpensive.
John