How to fix LG V40 screen discoloration issue (showing green glow or screen flashes)

The LG V40 is a great device. It sports one of the best set of hardware components anyone can get right now. The software experience is not bad as well because it runs the latest Android has to offer. But like any other smartphone, one of its weaknesses still lies on the screen as it can suffer from a number of problems, including the ones we cover below. If your LG V40 screen has discoloration or showing some weird colors that won’t go away, our suggestions below might help.

Problem: How to fix LG V40 screen discoloration issue (screen has green glow or screen flashes)

I’ve had my LG V40 for just over a month now. Within the last week, I’ve had a green glow coming from the right edge of the screen. I first noticed it while on the phone. Every time the screen would go dark while on call, I would see a line of blue light flash briefly on the right edge of my screen. I originally believed this was a glitch in the “sidelight” feature for notifications, so I disabled the feature. However, it did not stop the issue. Since that call, I noticed the green glow coming from the right edge, most noticeable on darker colors. In addition, the blue flash I saw earlier in the phone call has progressed to a full screen white flash/flicker on my entire screen when I’m on calls and I see it occasionally on my lockscreen. I’m beyond my return period and would rather not get a used “certified new” warranty replacement. Any suggestions? Thank you!

Solution: LG’s sidelight feature is designed to only light up a portion of the screen to show notifications. Sidelight, when enabled, should also only work when the screen is off, or if you put the device on sleep. It shouldn’t typically work during calls, when the screen is on. Still, the problem may be caused by a firmware glitch or by some other factors. To know if its fixable on your level, follow our suggestions below.

Refresh the system

Sometimes, this simple procedure can fix bugs that developed after the system has run for a long time. By manually forcing your LG V40 to reboot, you’re basically simulating a battery pull, which, in older mobiles with removable battery packs, was an effective way to refresh the system. If you haven’t tried this one yet, here are the steps that you can do:

Press and hold the Power button and Volume Down until the device powers off, approximately 8 seconds, then release.

Most of the time when this procedure is done, your phone will work properly but if not, then you still have other reset procedures below.

Clear cache partition

Sometimes, a phone may encounter bugs, app problems, or other annoyances when the system cache is corrupted. To check if there’s a system cache problem on your device, follow the steps below:

From the Home screen, tap Settings.
Tap the ‘General’ tab.
Tap Storage > Internal storage.
Wait for menu options to finish calculating.
Tap Free up space.
Tap Temporary files & raw files.
Select the following options:
Cached data
Clip tray temporary files
Raw files from camera
Tap Delete > DELETE.

Check for bad apps

Apps are sometimes to blame for Android issues. While a lot of apps in the Play Store are rated good, there’s also a significant number that can lead to problems due to lack of updates, incompatibility, or poor coding. To check if an installed app (third party) is causing the problem, you can restart the device to safe mode. In this mode, all third party apps will be blocked from running. So, the strange screen discoloration goes away when your device is on safe mode, that suggests there’s an app behind it.

To turn your LG V40 to safe mode:

Turn off the device and boot it back to safe mode.
Check for the problem. If charging works normally (by connecting the adapter to a wall outlet), proceed to the next steps below.
Uninstall an app that you think may be the cause of the problem. We suggest that you begin with the most recent ones you added.
After you uninstall an app, restart the phone to its regular mode and check for the problem again.

If you’ve found out that the issue does not occur on safe mode, you should further troubleshoot the issue by identifying the problem app. Safe mode won’t tell exactly which app is to blame so you have to spend time in narrowing down the possibilities. If you noticed that this problem happened right after you installed a new app, try to remove that app from the system first. If nothing changes, or if you have no idea which app it may be, do the steps below:

Boot to safe mode.
Check for the problem.
Once you’ve confirmed that a third party app is to blame, you can start uninstalling apps individually. We suggest that you begin with the most recent ones you added.
After you uninstall an app, restart the phone to normal mode and check for the problem.
If your LG V40 is still problematic, repeat steps 1-4.

Install app and system updates

Some minor bugs can be fixed by updating the operating system, or by addressing it directly with a coding patch. Make sure that the software environment on your device runs the latest version. That means keeping both apps and Android up-to-date. By default, your LG V40 should automatically download app and Android updates. If you changed this behavior before, be sure to check for app updates in the Play Store, or visit the software update option under Settings Menu for carrier or Android updates.

Reset All Settings

Restoring your LG V40 settings to their defaults is usually an effective way to fix minor software bugs and glitches. You can also try this troubleshooting step in this case. Performing these steps resets all system settings (e.g., ringtones, sound settings, display settings, etc.) back to their default values. Personal data such as downloaded apps and media (pictures, videos, music) aren’t affected. Here’s how to reset all settings on your LG V40:

Open Settings app.
Tap System.
Tap Restart & reset.
Tap Reset settings.
Tap RESET SETTINGS, to confirm.
If applicable, enter the PIN, password, etc.
Tap OK.

Factory reset

The most that you can do as an end user is to revert the software environment of your device to their factory state. If the cause of the problem is an unknown software bug, wiping the phone and returning all settings to their default settings might help.

Create a backup of your personal data.
Turn off the device. This is important. If you can’t turn it off, you’ll never be able to boot to Recovery Mode. If you are not able to shut the device off regularly via the Power button, wait until the phone’s battery is drained. Then, charge the phone for 30 minutes before booting to Recovery Mode.
Press and hold the Power and Volume down buttons.
When the LG logo appears, quickly release and then re-hold the Power button while continuing to hold the Volume down button.
When the ‘Delete all user data (including LG and carrier apps) and reset all settings’ message appears, use the Volume down button to highlight Yes.
Press the Power button to reset the device

Get help from LG (Repair)

Should none of the above suggestions work, you must contact LG or your carrier (if they provided the device) so repair appointment can be set up. Screen discoloration, especially persistent ones can be the result of allowing the phone to show a static image for a long time. This issue is called screen burn-in. Screen burn-in is permanent and can only be fixed by replacing the screen assembly. In some cases, apps designed to minimize the effects of burn in may work too. If you want to get a first-hand, professional advice about the issue though, you have to talk to an LG technician.