I have an old iPhone of which I want to reuse the LCD display. The thing is, I don't want to use it as an actual display but rather make a fancy lamp out of it. The question I have is how I can figure out which pins I need to put current on to make the screen shine. The idea would be to just have it connected to a simple switch to turn it on and off. Is there any way I should go about doing this?
The iPhone LCD pixel configuration (I think starting with iPhone 3G) is built normally black. If you just power the backlight (which you can do fairly easily) you will only get a slightly brighter black screen :-)
You somehow need to send data to the display controller to set the pixel voltages to their maximum value to get them to let the backlight through.
A quick search yielded this
It might be overkill for your application but there might be a simpler way to send white pixels. Maybe search for something like "MIPI DSI controller" since that is the data protocol the iPhone displays use.
On the other hand, I think some of the older iPods use normally white LCD displays. You may have better luck with those.
Finally, you can simply remove the backlight panel (plastic backing which is sometimes mirrored) from the back of the display which will reveal the LEDs and some diffuser films. These make cool lights.
The screen would have a backlight. You need to find the pins which power this part - no need to power the LCD in front of the backlight.
Here's an example of actually controlling the LCD, so it may also provide info on the backlight controls: https://www.youtube.com/watch?v=vCWGMM00ZEk
Do a quick search on "iphone screen pinout" and you will get lots of info. Also you may have to input a PWM or other signal to adjust the backlight brightness.