Looks like no one’s replied in a while. To start the conversation again, simply ask a new question.

iPhone 4 backlight flickering? Bad sensor?

I just bought a used iPhone 4 32 GB and I've noticed the screen flickers. It flickers almost barely most of the time and you have to be in a super dark room to notice (this doesn't bug me) but sometimes I've caught it flickering intensely for a small period. This has happened only twice, and I know it happened once when I was in a phone call (this may have been a software bug, as I've read if you initiate a data transfer the screen flickers) but at other times the screen will be totally black after unlocking the device, or just randomly turn black. I don't mean dim--I mean the device has a black screen with the image visible only in direct sunlight. This seems to happen ONLY when the auto brightness is on. I even have the brightness on the highest setting and check auto brightness and it will still do this. The home button and the lock button won't fix it. After about the third lock of the phone it will brighten back up. I'm wondering if anyone else is having this problem. My firmware is 4.3.1. I think the sensor may be bad. It doesn't have water damage (the headphone jack on the inside isn't white).


Does this sound like a hardware issue? The warranty on my phone is good until January but I'm still waiting on the confirmation email (after 24 hours) for it to be transferred into my name. How long does this usually take?

Posted on May 5, 2011 7:11 PM

Reply
4 replies

Nov 27, 2012 6:40 PM in response to metroidnemesis13

I had this same problem with an iPhone 4 and IOS 6. my screen would flicker a little here and there but the major problem was it would go out completely. I could only see it if it was held in direct light so I knew it was the backlight and not the LCD screen. As it turns out it's not a problem with a sensor or the software. It was a bad connection between the screen and the logic board. I unplugged the screen from the logic board and plugged it back in about 5 times in a row and when I powered the phone on the backlight worked perfectly. Hope this helps.

Nov 27, 2012 7:04 PM in response to Gibby19

Hi Gibby19,


It's possible that that was the problem. It sounds like that was what was happening on mine. Mine would go out completely as well but I know it was the backlight because you could shine a light into the screen and see what it was displaying. Regardless, it wasn't a software issue and I was lucky to have it still under warranty so I brought it to the apple store and they gave me a new one for free (swapped it out).

iPhone 4 backlight flickering? Bad sensor?

Welcome to Apple Support Community
A forum where Apple customers help each other with their products. Get started with your Apple ID.