The black screen on LG K51 can be the result of a minor software glitch or due to hardware issues such as a bad power button, battery, charging port, or LCD. It can even be completely dead if gone through liquid or physical damage.

There can be 2 scenarios. Either your K51 is dead, or it’s turning on but fails to reach the home screen.

If it’s not turning on at all, please head over to the below post –

LG K51 not turning on

 

If your K51 screen turns on but remains black, we need to find out the root cause to fix this issue. To make sure the phone is ON, take it in a dark environment and check the screen backlight. If the light is emitting through the screen, the phone is on.

Let’s go through the below troubleshooting steps to bring back our phone to life –

How to fix LG K51 Black Screen

Software Problem

Most of the time, a black screen is the result of a bad LCD. However, LCD replacement is a costly affair. Before changing the LCD we should make sure the issue is related to software or hardware.

First of all, let’s try to fix the LG K51 black screen issue without spending money –

1. Soft Reset – Force Restart

The most basic troubleshooting step is to perform a soft reset. It’s nothing but a restart. As the screen is all black, we cannot do a normal restart.

In such a case, let’s try to force restart the phone.

Press & hold the volume down & power button for 10 seconds or until the phone restarts.

If the phone restarts, but the screen is still black, the issue is related to the LCD.

 

 

2. Hard Reset via Recovery Mode

 

If the soft reset failed to restore your K51, let’s try to perform a hard reset via the recovery mode.

Let’s try to put our K51 into recovery mode.

 

Press the volume down & power button to turn on the phone. When the phone vibrates, release the power button and hold it again (Don’t release the volume down key).

Keep holding both the keys until your phone lands on the “Factory data reset” screen.

 

If you’ve got access to the recovery mode, try to hard reset the phone using the below link –

LG K51 Recovery Mode

If the screen is still black, move on to the next step.

 

 

Soft Bricked – Stuck on Boot Screen

If you failed to boot your K51 into recovery mode, try the download mode.

To get access to the K51 download mode –

• Get a USB Type-C data cable.
• Turn on your PC.
• Connect one end of the cable to the computer
• Press the K51’s volume up button, &  insert the other end of the data cable.

 

• This should bring you to the K51’s Firmware Update screen also known as the Download Mode.

If you’ve got access to the K51 download mode, flash stock firmware to restore your phone as per the below guide –

LG K51 Download Mode 

In case, the screen is still black, head over to the next step of troubleshooting.

 

Power Button not working

In a phone’s lifecycle, we press the power button thousands of times. It can get sticky after repeated use. Dirt or dust can also make it non-functional.

Make sure the power button is working. Try to wake up the phone with a double-tap on the screen using the knock-on feature. Your phone may be in sleep mode but fails to wake up due to the bad power button.

 

 

Bad LCD – Screen Replacement

If nothing worked, then surely your phone’s LCD has gone bad. LCD damage can occur due to water or physical damage. Using a bad charger can also damage your phone screen.

You can get an LG K51 replacement screen from Amazon for around $69. It comes with or without a frame. If you plan to change it yourself get a K51 LCD with the frame.

LG K51 screen goes black during Call

If your K51 screen turns black only during a call, the proximity sensor has malfunctioned. During a call, when we place the phone near the ear, the proximity sensor gets blocked and it turns off the screen. When we unblock the sensor, the screen turns on automatically.

If the proximity sensor has gone bad, the screen turns off when the sensor is blocked, but it fails to turn on when unblocked. Thus, the screen turns black during a call.

You can test your K51’s proximity sensor by doing the “Key Press Test” in the LG K51 Hidden Menu.

To get access to the K51 Hidden Menu, please go through the below post –

LG K51 Hidden Menu 

During this test, we need to block & unblock the proximity sensor as per the instructions on the screen.

 

 

The color change from blue to red indicates the proper functioning of the proximity sensor.

 

If your K51 is within the warranty, you should get it replaced for free.

Were you able to fix the black screen on your K51? Please share your experience via the comment section below.