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What makes an LCD screen go all funny?

16:12 / 21.01.03

The screen on my laptop is intermittently plagued with visual artifacts, which look sort of like that soup you see with your eyes squeezed shut. Husb thought that these might be caused by excess static electricity, and I read in this month's Real Simple that you can draw static away from your clothes with a wire hanger....

So I've been waving a wire hanger in front of the computer screen. Sometimes they go away, and sometimes it doesn't do anything. So I don't know if this is working at all, and I'm starting to feel a little bit stupid waving this wire hanger around like I think it's magic.

Would somebody demystify this for me?

16:51 / 21.01.03

I'm not sure what causes them, but I know when my dad dropped a LCD laptop on a tile floor, the whole screen turned into a psychedelic snowflake.

This page says that each pixel on an LCD screen has its own circuitry, so it could be something shorting certain circuits. Static seems unlikely though - I'd imagine (being utterly unqualified for this sort of thing) that there's something loose and conductive inside there, shorting things out.

Mordant would know more than me, I bet.

19:36 / 21.01.03

So you're saying that I'm wasting my time with this wire hanger?

20:15 / 21.01.03

I think so. Though I don't know enough to rule out static, I don't think a coat hanger would be a very effective tool for killing it. :-)

It could be something else, like the main power supply to the screen, or moisture inside, or a problem on the chips/motherboard ...

If you love your computer, take it to the shop.

20:17 / 21.01.03

But yes, Mordant will probably have an idea.

20:23 / 21.01.03

No wire hangers!

Less searchable M0rd4nt

20:24 / 21.01.03

Errrrr... *hides*.

Whilst I've got a pretty solid grasp of the basic physics and whatnot behind an LCD monitor (this site is good-- scroll down for the bit on LCDs), I'm hazy as to what could be causing the kind of effects Persephone is seeing. However, static sounds like a possible culprit.

I wouldn't have thought that the wire coathanger thing would do the trick. Can you think of anywhere that the static might be coming from? Are there any anti-static devices that you can attach to the screen?

Another possibility might-- and I should admit that I'm just guessing wildly here, so it's a big ol' might-- be electromagnetic interference of some kind. Are there any electric motors in the vicinity? (Although that would probably cause moving patterns of interference on the screen.) Any power cables?

Lastly, something might be disrupting the power supply to some areas of the screen. Have you checked for a loose connection somewhere?

If you're still drawing a blank, I suggest getting back to your supplier. It could be that you've just got a faulty monitor.

20:42 / 21.01.03

I do remember an older laptop of my father's had screen problems due to bad connections - you had to seesaw the screen back and forth on its hinge to get the screen to work properly.
But it didn't seem like the kind of rubbing-your-eyes things being described here.

20:52 / 21.01.03

Couple educated guesses:

1. Could be a cold solder joint on your LCD memory.
2. Could be a cracked wire on the flex cable that runs to your LCD.
3. Could be loose connection between motherboard/LCD board (there's a tiny PCB that hooks up to the LCD, usually glued to the LCD panel).
4. Could be a bad backlight circuit - these can go out and oscillate strangely.

Could you be more specific about the artifacts? Are there lines, or speckles?

The Return Of Rothkoid

21:21 / 21.01.03

Xoc: you fucking rule.

I don't know what causes it either; my old laptop used to get specky bits all the time, and they would fade in and out...

Less searchable M0rd4nt

22:29 / 21.01.03

Another thought occurs: Is anything putting pressure on the screen?

Elijah, Freelance Rabbi

22:47 / 21.01.03

1 dont let your cat sit on it when it is shut
2 all laptops eventually develop screen problems, although usually it is just a "whiting" effect, where blacks become grey and such
3 drop it lately? LCDs, all but the fancy new ones i think, are individual cells per pixel, any kind of shock or pressure can break the cells so the signals short accross the liquidy goo

11:26 / 22.01.03

I have very bad cats, but they deny sitting on the laptop. I don't remember dropping it ever...

It's swirly speckles, schwantz. They fade in and out, as Rothkoid describes. If you're watching a DVD, it shows on people's faces and make them look like they have hives. The screen doesn't flicker or anything. When you say "Could be a cold solder joint" do you mean actually cold, as in temperature? Because this has been happening only this winter. It's damn cold, especially in the bedroom where we watch movies. But also in winter it's really dry in our house, hence lots and lots of static electricity.

And Xoc... oh I wish so much that you could come to Chicago and see the shows that we do, I think that you would really love them. Have you looked on our website? I think that Ganesh must have been around, as we've gotten a spate of folks from Cross and Flame...

11:35 / 22.01.03

lessons we learn from this thread - don't buy used laptops from grant's dad...

13:25 / 22.01.03

Well, the scotch tape holding them together would be a really big clue in that direction.

If the "hives" don't move, it means you're facing pixel death - once a pixel goes, it only ever shows black or white from then on.

A "cold solder joint" refers to the condition of the components at the time of soldering - if one or the other isn't quite hot enough to melt the solder independently, the solder'll make a little bubble around the metal itself and the components (usually some sort of wire going into a circuit board) will easily wiggle loose or pull apart, disconnecting the joint.