Thank you for reaching out. I can certainly understand the frustration of the screen flickering causing your phone not to function as expected. I would be happy to look into this further for you. If horizontal lines appear on your Galaxy phone's screen while using Dark mode or when you are in a dimly lit area, there is no need to be alarmed. This is not a defect and there is nothing wrong with your device. Give this link a try for more information on the screen flickering in dark mode: https://www.samsung.com/us/support/troubleshooting/TSG01208985/
The next step would be to close all of your apps and restart you phone. This allows your device to have a fresh restart and clear any apps that may be lingering and using activity you may not be aware of.
Another option to try would be to test your device in safe mode. If your phone or tablet is misbehaving, it's possible that a third-party app is causing the issue. To figure out what app is acting funny, you can use the Safe mode feature. In Safe mode, your device won't run any third-party apps. I would recommend giving this guide a try to properly put your device in safe mode: https://www.samsung.com/us/support/answer/ANS00062983/
Another option would be to wipe the cache partition on your device. The system cache partition stores temporary system data. It's supposed to allow the system to access apps more quickly and efficiently, but sometimes things get cluttered and outdated, so a periodic cache clearing can help make the system run more smoothly. Give these steps a try to wipe the cache partition on your device:
• Turn off the device. • Press and hold the Volume Up key and the Bixby/Power key • When the Android logo displays, release both keys. • An 'Installing system update' message will show for 30 - 60 seconds before the Android system recovery menu options appear. • Press the Volume down key several times to highlight wipe cache partition. • Press Power key to select. • Press the Volume down key to highlight yes, them and press the Power key to select. • When the wipe cache partition is complete, Reboot system now is highlighted. • Press the Power key to restart the device.
The next step would be to try resetting your settings. This will bring your device settings to its default configuration. Don’t you worry, this method won’t delete your important files. Try this method to reset your network settings.
1. Go to settings
2. Go to general Management
3. Tap on reset
4. Tap on reset all settings
5. Tap on reset settings to proceed and put in password if necessary
The final step before service would be to factory reset your device. This feature will completely erase your personal information and data to make your phone a clean slate.
Important: Please save any information you need prior to the factory reset because your personal information may not be recovered.
If the troubleshooting is not helpful, the phone will need to be evaluated by a certified technician.
You can use the following link to find a list of service centers in the U.S. that can do the repair:http://www.samsung.com/us/support/service/location or by contacting customer support at 1-800-726-7864.
Samsung offers a variety of repair locations, including walk-in Samsung service centers. Select the product that needs service to find a location near you.
