Chosen Solution
Basically, I tried to replace the digi/LCD. After replacement, I get a backlight, but the LCD is just showing black. I restored it in iTunes, and did a couple hard resets to no avail. I tested out a second LCD (which is a 4S digi/LCD) on the board in this phone without taking it fully apart and everything functioned normally. I then took the phone apart and swapped the frame on the 4S digi/LCD to make it work with the GSM phone. After installation, I’m getting the same problem. I restored some more and did some more hard resets, and still the same issue. I went through the same steps one more time with another new part (test, then install) and still got the same exact issue. What exactly could be causing this? Could it be a problem with the board? I figured it wouldn’t be because these LCDs are working fine before installation. There are no tears or any damage to the parts at all. I’ve fixed well over 200 iPhones, and this is the first time I’ve had this problem. Help please! Also, this phone is missing quite a few screws (it was brought to me this way). All the grounding screws are in, but things like the dock connector shield is missing one screw, etc.
I’ve had this problem on the occasional 4/4S LCD, and suspect that some LCD flex just can’t handle bending prior to installation. You may want to test with an extension cable, or just wait until the LCD is installed. It’s also good to avoid connecting/disconnecting the LCD while the backlight is on.
