Dead pixel on CRT?

[Ribbit]

I've got a small black spot on my screen near the top left. It looks like a dead pixel (in fact it's smaller than a pixel at 1600x1200), but this is on a CRT screen. I'd swear it's in a slightly different place from day to day as well. Cleaning the screen doesn't help, and it looks like it's on the inside of the glass anyway. Any ideas? It doesn't bother me much, but it would be nice to get rid of it.

The monitor is a 21" Iiyama 503 (FST, not a trinitron).

[Admiral]

Do you have a nVidia card in the system by any chance ?

[Drizzt]

http://forums.murc.ws/showthread.php?s=&threadid=46350

[Ribbit]

Admiral - no, and I never have done. It's a G400Max.

Drizzt - it's not helping

[Kurt]

Re: Dead pixel on CRT?

Originally posted by Ribbit
I've got a small black spot on my screen near the top left. It looks like a dead pixel (in fact it's smaller than a pixel at 1600x1200), but this is on a CRT screen. I'd swear it's in a slightly different place from day to day as well. Cleaning the screen doesn't help, and it looks like it's on the inside of the glass anyway. Any ideas? It doesn't bother me much, but it would be nice to get rid of it.

The monitor is a 21" Iiyama 503 (FST, not a trinitron).

The only time I've seen sth similar was on the first iMacs, back in +/-'98. There was no other solution than change the tube.

Try to see if you can move the black speck by _gently_ shaking the screen. If it doesn't move, it's RMA time.

[TransformX]

Does degaussing help ? Does it make the black spot move ?

[Ribbit]

Degaussing does nothing for it - in fact the spot stays still while the image is swimming around.

I've tried giving the monitor a shake, and it doesn't seem to have made any difference. Do you know what might be causing this, Kurt (or anyone else)? Is it a sign that the monitor's failing?

Anyway, luckily Iiyama's got a great warranty policy (3-year on-site swap). Now I just have to check my monitor's still under it....

[Drizzt]

Ribbit, if it's still under warranty, what the hell are you waiting?

If not, try opening the monitor and clean the glass from the inside (the above thread was a suggestion, too )

[bsdgeek]

Could it just be a speck of dust inside the screen?

edit: What he said ^.

[Ribbit]

Darn. Warranty expired in November.

Could dust really get onto the inside of the glass? I'm sure if that was the case there'd be a lot more of it. (Especially the way I let my housekeeping slide sometimes )

[Taz]

Can you post a picture of it?

[Ribbit]

Camera seems to be playing hide'n'seek at the moment, but when I find it I'll try. Although this 'spot' is so small I'm not sure if the camera will be able to resolve it.

[TransformX]

We're just 3 months after.
Try talking to them anyway.

[LvR]

If you tried the monitor on another display-card and its proven that the screen is the culprit, then this "loose bits inside the screen" problem used to be a major issue long time ago when tube manufacturing technology and QA were still suspect........

The guys have learnt to include a sort of "particle collector" at a point just inside the neck of the tube - its basically a 15mm circular blob of some special metallic concoction that is held at about 1000V potential. Its purpose is to collect any stray bits of heater filament or cathode material as it disintegrates over time with use. If your tube were acting up because of the failure of this little gismo to do its job, you would find areas of several mm on your screen's that would seem to suffer form "out of focus" problems - this is clearly not your situation.

You either have something on the back of the shadow-mask or on the phosphor coating on the glass itself - either way, not much you can do about it other than mechanically moving it by banging the tube which is not a good idea at all .................

If the particle is as small as you make it out to be, it should continue to be an irritation and nothing more. If on the other hand the particle has a few friends of bigger size floating around and looking for a final resting place, then you may be in for some trouble - any particle blocking the path of an electron beam while sitting on the inside of the shadow-mask, will cause localized "hot spots" of the shadow-mask causing it to distort - if the particle is small the relative distortion is also small and the effect on the overall picture may not be noticeable. If however these localized hot-spots become large enough to cause a serious distortion in the shadow-mask, you may very-well find that localized discoloration will start becoming visible. If the "dirt" is sitting on the phosphor coating - no problem other than dark spots because the electron beam from the neck cannot reach a particular phosphor location to light it up - Either way, you gonna have to live with it.

[Ribbit]

TransformX - I did talk to them, that's how I found it was out of warranty. (I registered it with them when I bought it.) They wanted £120+ to do the repair (presumably a tube replacement).

Thanks for all the info LvR.