Hello everyone, my name is Kurt and have ran into this some problem 2 times in a row with the screen turning up blank w/ the back light on n iPhone functioning normally after a complete repair replacing that LCD-digitizer assembly.
Both different customers in a row one a 4G n one a 4s, both have there iPhones screens damaged from being dropped. With both there iPhone batteries completely dead n had to charge them.
Both times the screen showed a low battery indication icon.
The first person the battery had no charge n showed a low battery indication with the broken screen on still, guy just wanted has screen changed.
The phone apparently was already previously taken apart before me.
I proceeded like normal to replace the full screen. I got a blank screen
I tried three good screens on it, still the same problem with it.
I tied and did everything listed here except testing the IC and nothing worked.
I read about IC thing in ones posting n will looking to that and is full role in the iPhone 4.
I really inspected the M-board w/ a magnifying glass n it was fine.
The second person had also attempted a screen replacement on his, and succeeded up to the point of placing the back cover on with just a few screws missing n misplace. His condition was it dropped, broke his screen n bought a new screen on eBay, did the repair n got a blue type of screen he told me.
He could not fully get it back together, along with the problem, let is sat for 10days before calling me to look at it.
I looked at it tried to turn it on but nothing on the screen, I disconnected the battery n charger of course, disconnected the LCD digitizer connectors while it was still together, and connected a completely new screen assembly, put the battery contact back in plugged the charger in, n sure enough the low battery indicator on the screen came on, I waited and the apple logo started up like normal n the phone worked.
After that I turned it off, disconnected the battery & proceeded to install the screen in and after the assembly process I had it to getter n the screen turned up blank w/ the back light on n the iPhone functioning.
I also did everything as the procedure and steps to finding to mistake n problem w/ the blank screen problem. I literally read all the posts here up to my posting now and have done everything listed here to solve it and nothing.
I also have an iPhone 4s that is a black listed Verizon n use that for testing screens.
I just recently encountered an almost similar problem but the screen stayed white for a second after powering it up and the apple logo came up as normal, as I disconnected it and reconnected it the screen was flickering like a bad tv channel jumping with lines.
That there was a loose connection because it stopped as I played with the connection for the LCD part, digitizer was fine the whole time.
I took a video of it while the screen was jumping and everything.
Sorry I made this posting too long, but tried to be descriptive as possible to help in greater details, in hoping my exp will help others to add up the cause of this problem.
Personally I think the new version iPhones do this but then again I have taken well over 50-60 iPhone 4 n 4s es apart and fixing them, I have never damage any mother boards or any parts but one flex cable for the digitizer on an iPhone 4G when first starting out.
I have taken my very first iphone 4g apart over 10 times to use as testing parts in some cases, yes my own iPhone at the time, and never saw this issue once till recently with other people's iPhones.
I truly n strongly think it is software related in my case n in some other cases as well.
Ps: There is a thing with the screen being but on while the iphone is powered on. The LCD screen will not register the display to come on till u turn it off n then back on again To restart it.
I hope all this adds to help to the pile of the mysterious blank screen problem that a lot people are getting now.