First and foremost, I’m buying a new phone relatively soon because I need to replace my current one, this thread is more of an “interest” thread than an “I need help” thread because I can’t imagine what could be causing this to happen.

About a week ago, I dropped my iPhone (with an otterbox case) very hard face down on the kitchen floor. Later that day, I noticed what looked like a black bundle of pixels on the lower left portion of the screen. As the day progressed, one line of black pixels “grew” from one end of the screen to the other. As more days went by, the line grew, pixel by pixel and row by row, into a horizontal black line around 5 rows wide. The dead pixels then skipped a few lines and gradually formed another random single-pixel-wide line.

At this point, I was left with two small lines of dead pixels across my phone, one wider than the other. Next, the lines became fuzzy looking, the top line actually shrunk and some pixels started working again towards the center of the screen, and it’s now changed color into purple and pink. This all took around a week to unfold. It’s honestly been pretty fascinating to watch damage progress and unfold over the course of a week.

Does anyone know what causes this or what mechanisms in the phone would lead to such a delay in the damage showing up then reversing itself partially?

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Posted by Lonnie Utah

Utah!

Member since Jul 2012

24026 posts

Posted on 1/2/24 at 8:45 am to Forever

quote:
Does anyone know what causes this or what mechanisms in the phone would lead to such a delay in the damage showing up then reversing itself partially?

I don't "know" what happened, but I can speculate based upon basic knowledge of how LED screens operate. LED screens are a matrix of very small Red Green and Blue LED lights with the ability to change brightness. How the brightness is applied to each of the RGB channels allows them to reproduce about 16 million colors for an 8 bit device (256 brightness levels/channel), 134 Million colors for a 9 bit device (512 brightness levels/channel) or an astounding 1+ Billion colors for a 10 bit device (1024 brightness levels/channel). (As an interesting side note, the human eye can only distinguish about 1 million unique colors...)

Anyway each of these LEDS has three inputs, power, ground and data. The data signal controls a resistor or group of resistors that changes the voltage to each channel of the the LED producing the brightness for each channel. It then passes the data signal to the next LED. It's possible that when you dropped it you damaged one of the three inputs to the led causing an over voltage or under voltage situation. Eventually this would either "fry" or disconnect the first (or last) led in that row. Since all the LED's in a row are wired in series, this failure mechanism would cascade down the row until it damaged the entire row.