Over the course of the past two weeks, I’ve had a very interesting experience with the LCD screen in an old flip phone cellphone. On one moment, I made a bad touch to it and very nearly lost it all. Literally. And, in the following moment, I literally came back with a healing touch and completely restored its original, fully functional state. Overall, this was a very great learning experience with lessons to teach for working with LCD screens modern electronics, especially DIY hobby projects where you are likely to handle the bare LCD screen components before all protections are installed.
So, what happened? What did I do that started my bad touch to the screen? I wanted to check my phone quickly while I was laying in bed, but I had to turn on my phone first because it was powered off. To do this, I was first ruffling around frantically in my bed on a winter day when the air was dry, then I quickly reached over to my phone on the nearby table. I had to open the flip phone to power it on, and while I did, I made a few accidental touches to its internal LCD screen. Herein lies the problem. All that ruffling around in my bed on a dry air winter day built up a considerable static electric charge, and reaching over quickly to touch my phone didn’t help either, as that meant that the static charge didn’t have time to slowly dissipate. And, being that my phone was on my table, my table was made of a more conductive material, so that meant touching things on my table would lead static electricity to discharge through those things more readily to my more neutralized table, and the two ends especially had differing electric potentials at this moment.
Yes, what happened was that my phone’s LCD screen met with electronics’ arch-nemesis: electrostatic discharge (ESD), the “touch of death.” And thus began the problem.
Left behind was a swipe pattern of several black spots where my finger touched. Oh no! Dead pixels? If they’re not, maybe a power off an a power bavck on will remedy the problem. Nope, likely dead pixels. But, when you looked at the spots carefully, you could tell they weren’t totally black. So these pixels weren’t totally dead, or maybe this was something else like bad video RAM. In any case, powering off, leave it sitting for a few hours, then power back on can be a great way to heal electronics when they behave in a failure mode similar to a tripped polyfuse. So I did that, power off for 8 hours, then power back on. Nope, dead pixels don’t heal themselves.
But, here’s the surprise. The next day, I kept my phone in my pocket all day long, and upon removing it, I noticed that there were not as many dead pixels anymore. Wait, dead pixels don’t heal themselves? This is where you turn around and say, “Not quite, dead pixels can be healed, if with a little external assistance.”
So, over the course of trial and error that I will not detail here, this is what I’ve learned. First of all, here is a reference of what Wikipedia has to say about LCD screen burn-in and how to reverse it.
20200125/https://en.wikipedia.org/wiki/Screen_burn-in
20200125/https://en.wikipedia.org/wiki/Image_persistence
Second, Wikipedia’s knowledge was pretty much not applicable to my particular circumstances. So how was it solved? Heat. Heat alone, actually, was the “healing touch.” Exercising the crsytals via display and power off may have helped a little, but by any means it was only useful for starting the healing process. The rest was simply exposure to the correct amount of heat, and a consistent heat at that. What better source than your own human body. It maintains consistency in its temperature quite well, not to mention us being water-logged humans being a big part of this fact. Through sufficient heat exposure, by keeping the phone in my pocket and also sleeping with the phone in my pocket to guarantee sufficient continuous, uninterrupted temperature exposure, the problem was completely eliminated.
What happened when I was not consistent in exposing to to sufficient temperature? The LCD screen deformity grew. Growing out with spider-like veins, or the claw-like look of a dead tree as a haunted house prop. Growing like a viral infection threatening to consume my entire LCD screen into useless “crystalization,” useless rock content. Because crystals, of course, take on the properties of their neighbors: if a crystal has bad neighbors, it too grows up to be a bad crystal. In particular, cooler temperatures seemed to stimulate the deformity to grow faster.
And, furthermore, getting the visual deformity to completely vanish was not enough. Once there was no more deformity visible, the screen then had to be exposed to heat for a few additional hours to guarantee that the deformity would never come back. Otherwise, it came back and started growing once again.
So, there you go. Now you know one good way to heal LCD screens, expose them to sufficient heat for a sufficient period of time, say 100 degrees for 48 hours continuously.