Samsung Galaxy Phone Black Screen

Before undertaking any of the more time-consuming solutions below, here are a few fundamentals to get you started.

• Charge it. If you get a battery logo onscreen, it needs more power before it can boot. Leave it connected for at least fifteen minutes, but an hour is best.

• Force a restart. Press and hold Power and the Volume Down for 20 seconds.
• Remove all accessories and peripherals. They may be preventing proper wake.

The front-facing camera, and a host of other sensors populate the top edge of most Samsung phones. The Ambient Light Sensor, or ALS, sets the screen’s auto brightness. If it's malfunctioning, the screen may not be black at all, just dim.

• Move to a darker environment and verify nothing is on screen. If you can see your screen now, attempt to turn up your brightness.
  • If possible, enable auto brightness. The location of this setting varies across versions of Android, but is typically in Display settings. If the brightness changes, the ALS is working properly.
  • If auto-brightness was already enabled, the ALS may be at fault. A failed sensor can lead to incorrect data about ambient light levels.
• The location of this sensor varies. If you see an additional cutout on the screen near the front facing camera, that is a typical location. These sensors can often "see" through the display panel, so the cutouts are trickier to spot. Do some cross referencing with housing components to spot the sensor cable.

Although most display failures seem obvious, the display may not work properly due to something amiss internally, even without visible damage,

• Look closely at your display for signs of breakage. Changing your viewing angle may help catch small hairline cracks.
• Check internal cables for signs of tears or other damage. Have a look at the Guide for your Galaxy phone model for more specific information.
• If you find damage or software fixes have not made a difference, replace the display.

Like the main interconnect cables that run across the battery in many models, the display connects are often very wide.

• Try simply reseating the cable, especially if you have recently done work on your phone that required disconnecting this cable.
• Inspect the cable for damage, especially if there is any cracked glass. Rear glass is a primary candidate here since it will be more exposed to this cable.
• Replace the cable if you find damage, or suspect it is faulty.

The motherboard is the hub for the vast majority of your phone's functionality. Any number of the small components on the board may have failed or become damaged. It is a safe assumption of cause if nothing else on this page has worked.

• Check for obvious signs of a board issue—burned or cracked components, liquid residue, corrosion, or bend. If there are signs of liquid, the iPhone Liquid Damage Guide might help. Don’t worry, these guidelines apply to all circuit boards with liquid damage.
• Pay close attention to the display connector. They are often quite sizeable and may sustain damage if the phone is bent or undergoes a significant drop.
• Replacing the motherboard is often the most practical solution for a DIYer in this position.