Weird Monitor Problem

[Scott Baret]

Thought I'd post this here and ask for some insight.

I've got a 12" Apple monitor (RGB, LC style) and it's got a slight problem. There appears to be a speck of dust stuck in the screen. It's like a dead pixel but CRTs don't get dead pixels.

How would I get this out? There's no degauss button so that's out as an option. Any other suggestions?

 

[Danamania]

Thought I'd post this here and ask for some insight.
I've got a 12" Apple monitor (RGB, LC style) and it's got a slight problem. There appears to be a speck of dust stuck in the screen. It's like a dead pixel but CRTs don't get dead pixels.

How would I get this out? There's no degauss button so that's out as an option. Any other suggestions?

My iMac has one of those, a little fine dot inside the screen. It's either some crud that was inside the tube when it was built that's decided to stick somewhere, a manufacturing defect in the mask, a manufacturing defect in the phosphor triads, or something similar along those lines.

And basically - they don't go away. If it's the first option, shaking the screen about might dislodge it - but there's no telling whether that'll make more muck fall about inside the display, or just make it move about to another location.

Dana

 

[tomlee59]

You wouldn't want to degauss it even if there were a button, because it would do no good. In any event, the degauss circuitry is enabled briefly each time you power up. Because your problem is not due to magnetism, demagnetization isn't the answer.

As danamania said, if it's really a piece of dust, then there's not much you can do other than to rap on it. If it really bugs you, go ahead and give the monitor a good slap on the top or sides. I would do this after letting the monitor sit unpowered for a day or two (to discharge any HV that could keep that speck in place through "static cling").

I wish you good luck!

 

[Byrd]

Similar things happen when the CRT tube lets a small amount of condensation in - I've come across a few screens lately that have a small dot to a mottled patch on the display (the worst being an eMac 700 I was given, not a pretty sight while turned on - psychadelic city!)

JB

 

[tomlee59]

Sorry, Byrd, but CRTs operate under such high vacua that no contamination by moisture occurs. You have no idea just how close to perfection the vacuum must be for a CRT to work at all. A leak sufficient to induce moisture-related damage to phosphors would cause much more dramatic artifacts.

If you see mottling/rainbows/etc. on a color CRT, suspect a degaussing issue, or a mechanically damaged shadow mask. But a leak? No way.