What kind of stuck pixels are these and how to fix?

[Skykid]

Hey chaps,

Got what I'm guessing is a refurbed LCD LG panel (minus chassis) that I'm using for a project, and I've got an irritating stuck pixel problem. In one small area about the size of a fingertip is a darkened patch. Residing inside that patch is a recurring stuck pixel and several others that will suddenly appear when applying pressure to the area.

The area is darkened like a smudge, but not black, and the image is still visible under it. The recurring stuck pixel is most obvious on black screens, and is usually red.

When I massage it, I often see other stuck pixels appear nearby, usually blue. I can massage it successfully until all stuck pixels are gone, but then after some time (or moving the panel around) it likes to flicker back to life. The surrounding smudge never disappears.

I tried a hot towel, massage, but not yet flashing RGB screen (because it's a little tricky to set up currently).

The thing is, usually stuck pixels appear as one, but I don't understand the permanent darkened smudge or why several other blue pixels often appear inside when pressure is applied. The recurring red pixel also occasionally switches to blue during massage times too.

Thanks for your input!

[Guspaz]

Perhaps the monitor took a blow in that area, and is now slightly deformed, permanently putting pressure on that area?

[Ed Oscuro]

Aside from the larger dark area, there may also be dust in the screen. Lots of people have had problems with this even in factory-new flat panels with no vents for dust to get into; their factory just isn't as clean as it could be. However that alone won't account for the dark spot, unless it's a coincidence.

Massaging the screen is also a good way to get nasty brightness uniformity problems (or make them worse) if the layers fall out of alignment - at least some modern backlit LCDs seem to be really prone to problems when moved, let alone rubbed on the screen. This also puts the transistors themselves at some risk of further damage.

Sad to say there probably isn't anything you can do to help this other than process an RMA.

[Skykid]

So there's nothing I can try myself then?

The dark area surrounding the recurring pixel isn't black or anything, it's like a faint smudge - noticeable if you look, but not much.

I've read a lot of stuff about stuck pixels and fixing methods, but this one (and the others that occasionally appear nearby when pressure is applied) are weird because they can be massaged away for half the day, but then like to flicker back to life now and then.

If I can manage it, do you think an RGB video loop might help, or not for this kind of issue?

[gray117]

You're likely stuck with the 'shadow' it'll basically be a physical fault, given the faulty pixels sit in the middle of this it's all likely part and parcel of the same fault - likely a slight seperation occuring. If warming/massaging/pressure temporarily lessens such an issue there's probably physical separation occurring in that area and you're temporarily pushing/bonding parts back into place (shadow) and/or reconnecting a signal (stuck/dead pixel).

You can try slightly more drastic pressure/heat over time, perhaps followed by gentle but applied cooling (don't shock cool/freeze) ... chances might be more in favour of causing more damage than fixing your issue... but if it's kind of fucked already so what you got to loose?

Manufacturers will not repair such faults as such - just replace components - chances are fault is permanent or will re-occur with operational heat etc.

[Ed Oscuro]

Dead pixel faults as well as a severe patch of bad gray uniformity (which you definitely have got) are both grounds for an RMA, I'd think. It was damaged in shipment.

Sure, some people have documented improvement in some LCD monitors, but whether this can be successful or make things worse likely varies depending on exactly what panel it is. If you've already tried rubbing it and gotten nothing, I'd not keep trying that. The thing probably needs pressure applied to the layers in back of the LCD (where you can't get to them), and pushing on the front is just likely to aggravate the separation problem, I'd think. In any case, this isn't going to fix a transistor knocked out of commission by an impact. I'd get that RMA rolling, if you can (though it sounds like this is actually a preowned panel you're getting secondhand).