If it's flickering, it's probably a bad solder joint or a
fleck of cathode material shorting out the CRT drive.

In the former case you can take a fully insulated tool (screwdriver
handle, not tip) and tap the circuit board in various places to see if
you can get a correlated flash. This will lead you to the bad
joint.

If the CRT, taping the neck of the tube will cause the flake
to vibrate, flashing in sync with the taps.
Check the CRT socket for bad joints. It's fairly common to
have bad joints here from mechanical stress.

ALWAYS follow the rule "ONE HAND IN THE POCKET" when poking
around a exposed, live CRT system. It CAN save your life.

Stay away from the big red lead the goes to the side of the
CRT. It has 22,000+  KILLER volts and you will not likely
survive arc over contact with it.

That you have red outlines is a bit puzzling but suggests
an open circuit where the red data is being weakly capacitively
coupled across the break.

Let us know what you do find.

DISCLAIMER: You follow the above advice AT YOUR OWN RISK.
CRT circuits have LETHAL voltages present. 22kv around the
CRT. 5kv at the CRT socket (Focus). 300V at the cathodes.

Keep ONE HAND IN YOUR POCKET to prevent across the chest
current paths.

Robert

John Pearson wrote:
> My 19" CRT monitor displays red as black. I get a red outline on most red objects, but the bulk of the object is just plain black. Sometimes it works properly, but then it will start to flicker red to black, then stay black.
> 
> Any chance I could find the problem and repair it? It is a high end monitor, but if I wreck it, no real lose.
> 
> John
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