Dead Pixel... on a CRT!!!

[888888]

Yesterday, I noticed that my Mag 19 inch monitor has a little black dot near the bottom of the screen. It is not dirt and comes back after the monitor is turned off.

I did a little research and found a site that said that, like LCD monitors, CRT monitors can also get "dead pixels" although it is not common. It could be dust inside the screen or a burnt out phosphor. I am not sure if the dot was always there but it is more likely that it appeared recently since I never noticed it before.

This has got me really bummed. One of the reasons I stuck with CRT instead of getting an LCD monitor is because I HATE dead or lit pixels. I can't stand even one. And here I have one on my CRT. And I really like this monitor too. Now I will always stare at that little dot.

Anybody else experience this phenomenon of CRT dead pixels? Any suggestions or ideas? Thanks.

[BJ_M]

it may be a piece of dirt or metal in the screen ... you MIGHT be able to dislodge it by a fairly good wack to the monitor ...

be carefull to not hit to hard ..


try degaussing a bunch of times


see if a magnet might be able to make it move (works better off) .. dont hold the magnet in one spot to long ..

a bad phosphor wold be really rare -- that would ussually make a bright spot more than a dead spot ..





dont open monitor to try to fix yourself -- deadly voltage (current) inside ..

[BJ_M]

some monitors also have (ussually 4) dead spots for alignment at the factory ..

im not talking about the wires you see on sony tubes ..

[thecoalman]

im not talking about the wires you see on sony tubes ..

Evertime I work with images with white backgrounds. WTF is that....

[Cobra]

Get a TFT monitor. Dead pixels are few and far between on modern displays.

If you don't like them though then I suppose you could look at having it specially repaired or buying a new CRT.

[BJ_M]

im not talking about the wires you see on sony tubes ..

Evertime I work with images with white backgrounds. WTF is that....

Sony's Trinitron design uses a variation of the shadow mask called the aperture grill (or guard grill). Rows of very fine metal strips run vertically down the screen, separating columns of coloured phosphor which are arranged in alternating stripes of red, green and blue. This configuration allows the phosphor strips to be placed closer together than conventional dot triads, and the fine vertical wires block less of the electron beam than traditional shadow masks, resulting in a brighter image, and less thermal buildup and distortion. Coupled with changes in the way that the electron guns are arranged, this design results in a crisp, bright image. However, the vertical strips are so fine that they can be set into motion when contacted by the electron beam (thermal changes) . This would result in a shimmer on the screen which would be quite distracting. To remedy this, Sony puts horizontal stabilizing wires across the vertical ones. This reduces shimmer, but results in one or more fine horizontal lines being visible on the monitor. As mentioned above, the number of lines increases with monitor size. Usually, these lines are only visible to a discerning viewer when looking at a bright, solid background. If you're an experimentalist, try gently smacking the side of a Trinitron monitor, and look to see the wires shimmer. Basically, the horizontal lines are a minor trade-off when compared to the superior brightness and vertical flatness of the Trinitron screen.

What follows is a statement from Sony about their aperture grille design:

Since its introduction in 1968, Sony has produced more than 70 million CRT's. Award-winning Trinitron CRT's are used in a multitude of applications, including high resolution displays for the computer industry. Today, Trinitron CRT's are used by Sony and other leading manufacturers to meet the ever increasing demands and expectations of computer users throughout the world.

One of the unique features of the Trinitron CRT is what is called the Aperture Grille. An Aperture Grille consists of a series of long vertical slits fastened with strong vertical tension to a steel supporting frame. Electron beams pass through the Aperture Grill to illuminate phosphor on the faceplate. The vertical tension of the Aperture Grille absorbs any thermal expansion, thus eliminating the problem of doming or color spill and resulting in a superior picture quality.

Since the CRT requires a vacuum to function, a damper wire which is approximately 15 microns in diameter is strategically placed on the Aperture Grille to reduce susceptibility to resonance. The "line" that some customers see on the screen is not a fault but the damper wire which has always been an integral part of our Trinitron technology.

[Cobra]

I used to use a 19" Trinitron screen before I made the jump to a TFT display. It had not one but two of those tiny wires, one top and one bottom. You don't notice them unless you look closely.

[BJ_M]

sony tubes for pc 's always have 2 up to at least 22" wide screen

they dont bother me either ..

[888888]

it may be a piece of dirt or metal in the screen ... you MIGHT be able to dislodge it by a fairly good wack to the monitor ...

be carefull to not hit to hard ..


try degaussing a bunch of times


see if a magnet might be able to make it move (works better off) .. dont hold the magnet in one spot to long ..

a bad phosphor wold be really rare -- that would ussually make a bright spot more than a dead spot ..





dont open monitor to try to fix yourself -- deadly voltage (current) inside ..

Thanks for the advice BJ_M. I will have to try those things.

Personally, I wouldn't mind those lines if I had a Sony monitor. Things only bother me when they are DEFECTS or BROKEN.

[Roundabout]

I know what you mean, it's kind of like when you chip a tooth, your tongue keeps going back to it involuntarily

The 17" LCD I bought a few months back had one stuck pixel and I took it back and got another for the same reason. I can't stand to have a permanent flaw in a new product like that. You'll see it every time now when you look at your monitor, driving you crazy.

Not bad ideas that BJ_M came up with, but I agree, if you use a magnet, don't keep it there long, you could permanently magnetize it, causing color flaws in that spot. The built-in degausser might not be able to overcome the magnetism, making you get an external degaussing coil to correct it.

[thecoalman]

sony tubes for pc 's always have 2 up to at least 22" wide screen

they dont bother me either ..

They don't bother me either so much so that I forget about them up until now and see them all the time again .....I see them on a image with white background. Of course the first thing I think is WTF is this line going through my image until it hits me it's those stupid wires. I was aware of what they were because when I first got the monitor I immediately noticed them, at first I thought there was something wrong with it until I saw info similar to what you posted above.

[Skith]

Nec/Mitsubishi Dimondtron monitors also have the two faint black lines. I am using a Sony CPD-G400 right now, though it is finally starting to show problems.

[888888]

Well, I tried tapping the screen and lightly smacking the monitor, to no avail. I still have bad memories of a friend years ago putting a magnet to his CRT screen and it leaving a magnet shaped discoloration permanently. So I don't think I want to try that.

Degaussing did not dislodge it either.

Anyway, thanks for everybody's replies. I will update if the situation improves.

[BJ_M]

how about shaking it

[888888]

I remember when I bought the monitor and first put it on the table, it sort of went crash-bang (those 19 inch CRTs are heavy). Therefore, it is likely something might have gotten dislodged then and become stuck, blacking out a pixel.

I've tried shaking it now and it doesn't seem to help though.

[LSchafroth]

I'll give you $50 for it. I need to built a projector and it would wokr nicely for me.

LS