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macrumors newbie
Original poster
Jun 1, 2013
Hey everyone! This is my first post on this site. I have been on here for a week reading and following some tips but none which have helped me at all so I will explain what is happening.

I have a iphone 4 that had a broken screen. I went about replacing the screen (not the first time i done this) and when I turned the phone nothing happened.

I took it apart and tried another screen and got the same results.

I took the phone in a dark room to see if there were any light of any sorts and to my surprise the screen is working, but it wont display anything. Still in the dark room I disconnected the battery and connected it again. I pressed the power button and the apple logo flashes very very quickly and goes away, the phone continues to boot up successfully. The mute/volume keys make sounds when pressed, the home button will activate the voice assistant and that works fine. But nothing can be seen. If i press the power button on the phone the screen will flash so quickly you cant make out what screen its even on, thankfully for me I know what screen its on because the slide to unlock is available on the bottom of the phone.

I have tried pressing the power button and swiping the slide to unlock fast but it goes away too fast for me to be able to do anything, and if it was not a dark room you would think the screen is not on at all.

I have done a reset
I have held both power/home buttons down
I tried DFU
I have successfully restored without error
I can receive calls
I can take screenshots with the camera and it makes the sound
I have used windex to clean contacts of connectors
I have tried 3 batteries
I have tried 3 screens
I let the phone charge overnight, rinse and repeat all the above with the same results
I have tried the mute button and I get a responsive vibration when activating the switch on the side of the phone

I verified all connections and nothing is damaged
all 3 LCD screens have no tears in the cables that pass through the iphone frame

I just tried another screen (#4) and the same problem is happening. This is not the screen, but it seems like it just dont fully light up. The LCD lights up for 1/1000th of a second and goes away and will do this every time I press the power button.

I have attempted to take a screenshot and open iPhoto to determine what screen I am on and this failed. I have tried using the voice assistant to try to guide me through the screens and this fails as well

After the restore I connected the iphone to itunes and got a error saying phone cannot be activated and to take it to a service center for activation (had no sim card installed and this step will need to be completed after I can see the light)

Does anyone have any suggestions or ideas what the hell is happening to this phone? It was dropped, screen broke and typical screen replacement, until this started happening. The original broken screen used to work fine with the cracks on the screen, and even when trying to use that same broken screen, all I get is a very fast blink on the screen and the phone then goes black and boots up fine with no display.

Any advice would be great!



macrumors 601
Apr 30, 2012
did you bend, rip or tear the LCD flex cable? also, where are you sourcing these new screens from?


macrumors newbie
Original poster
Jun 1, 2013
There is no tears or bends that could crimp or damage the cable

The screens are ordered online through a site where I never have problems.

I dont think its the screens because as I said in the description the original apple screen was broke, and after testing and having these issues with the screens, I placed the original broken apple screen back on and the exact same thing is happening to that, it wont turn on, it just flicks quickly when I press the power button, but the flick is nowhere near bright, in a dark room you can see the screen on, but if you pushed the power button during daylight, you wouldnt even notice the screen flash because its so dull/dim.

This is the first time I had this issue which is why I am here, usually never have problems, except now.

Brian Y

macrumors 68040
Oct 21, 2012
That sounds very much like a power issue.

At some point there's been a surge/something inside your phone which means that your phone is now no longer providing the correct voltage/current to the LCD. Hence why it flashes on then off and why it fails the hardware test, telling you to take it to a service center.

Only thing you can do is replace the MLB (or the phone) - or to take the MLB out and try to find the fried component - wont be easy though.


macrumors 6502a
Oct 24, 2012
Can you install and test both of those screens on another iPhone 4 to see if they work? If so, then doing so will validate whether the issue is with the screens or the phone.
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