In this post, I have enumerated some highly recommended methods used to deal with screen flickering problems with the Apple iPhone 6 and 6 Plus, whether it's due to a hardware damage or software bug.
If the problem is triggered by a software glitch, here are your options:
1. Reboot your iPhone.
If this is the first time you noticed your iPhone screen flickers, then try to reboot your iPhone. Do the same if the problem occurs while using certain applications. After the restart, observe your iPhone and see if the problem persists.
Meanwhile, if you suspect a broken Cydia tweak is causing your iPhone screen to flicker, then you can boot into safe mode by holding the Power and Home button until the screen goes black. Continue with the following steps:
- Release the Home screen but keep holding down the Power button.
- When the Apple logo shows up, hold the Volume Up key until you see the springboard.
- You will know if your iPhone is already in Safe Mode if the tweaks are no longer found in the settings menu.
- Now observe your iPhone for a few minutes. If the problem is gone, then most likely it's a faulty app or cydia tweak is causing it. Your next option then is either to disable or remove the broken cydia tweak (most likely the last tweak you've installed) from your device.
2. Adjust screen brightness.
Other iPhone owners who have encountered the same problem on their phone screen have obtained temporary fix by adjusting screen brightness. To do so, go to Settings-> Display & Brightness-> disable Auto-brightness and drag the Brightness slider down to lower screen brightness.
3. Turn on Reduce Transparency.
Aside from adjusting the iPhone's screen brightness, you can also try to enable or turn on Reduce Transparency feature. This is a display feature available on iPhones running iOS 9 and later versions. To access this option, go to Settings-> General-> Increase contrast, and toggle the switch next to Reduce Transparency to turn the feature on.
4. Check memory status.
Another thing you need to consider is your phone's internal memory. Sometimes, the phone misbehaves when the internal memory storage is getting insufficient to carry out additional processes. Aside from screen flickering, other indications of possible insufficient memory include a frozen or unresponsive screen. If you think your iPhone's memory is almost full, you can delete any unwanted contents such as unused apps, old text messages and media files, and other useless details stored in your device.
5. Hard reset your iPhone.
This must be your last resort if you suspect the problem is caused by a software glitch and none of the aforesaid workarounds is able to fix it. Please note though that performing a hard reset or factory reset will erase all personal information including contacts, and other customizations in your iPhone. That said, be sure to back them up before you start.
If the problem is caused by hardware damage, here are your options:
Screen flickering problem that occurs after the device was dropped or exposed to water is most likely due to a faulty hardware component, particularly those that are attached to the display circuit board. Sadly, your only option in cases like this is to take your iPhone to an authorized Apple technician for hardware check and repair. Unless you are skilled enough to do the hardware fixing and that you are willing to take the risk of adding more damage to your iPhone, then you can go ahead and give it a shot.
You then can start by cleaning up your iPhone screen, trace the damage or loose connections in the internal components, re-attached the cables, or finally, do a screen replacement.
Loose connections within the LCD connectors and Home button can also be the culprit. A user who have encountered screen flickering due to connection issues suggested a gentle push in the center can help.