How to Fix Samsung SGH-F490 Black Screen

What are the causes of a black screen? Hardware reasons and software reasons. The former include a malfunctioning screen, a defective matrix, problems with the power button, etc. The latter include system shell errors, application errors, virus attacks and others. So let's go through the possibilities to fix black screen on the Samsung SGH-F490.

Basic algorithm

Press the power button. If the screen works, everything is OK.
Restart the phone. Press the power button until it vibrates.
- If the logo appears during a restart, there is a problem with the phone software or an application.
- If the logo does not appear, it is a hardware problem. You need to take your phone to a service centre.
After a restart, the screen may or may not work.
- If the screen works, the problem is most likely due to a bug in an app or shell. Fixes for such errors are often noted in the upgrade logs. You can check these periodically to see what the black screen is all about.
- If the screen doesn't work but the phone itself does - there's sound, vibrations - then it's probably infected with some kind of virus. For more information on how to rid your device of viruses, see Software Causes.

Resolving problems with the hardware

First charge the mobile phone. If, after a few seconds, a picture appears showing the battery gradually filling up, or a percentage figure with a lightning sign, all is well with the hardware.

Matrix not working

If the screen does not light up and you are sure that the charger is working, the problem may be with the matrix. The malfunction usually occurs when the screen of the mobile phone is damaged. Without disconnecting the phone from the charger, try shaking it in different directions. If the screen lights up or the image appears and then disappears, there is a problem with the sensor.

Also try examining the phone from different sides. If there are chips, cracks or gaps between the screen and the casing, the problem may also be related to the sensor.

There are ways to repair such damage at home. But it is much easier to take the mobile phone to a service centre.

Inoperable power key

Usually, the problem occurs in two situations: when the button starts to stick or when the phone has fallen into water. In the first case, it is sufficient to clean the recess for the button. However, it is not recommended to do this yourself - there is a high probability that the power button will be damaged or break off.

In the second case, the contacts are probably oxidised. It is impossible to repair them at home without special equipment. If the power button does not work, you must take the phone to a service centre.

Light intensity

Many users turn down the brightness of their mobile phone in dark places so that it does not shine in their eyes. This makes sense. However, as the day goes on, they forget to turn it back on. Because of the design of the screen, especially the viewing angle, there can be a black screen effect. Roughly speaking, when it is bright outside and the brightness of the phone is minimal, the image becomes indistinguishable.

This is easy to fix. Just go into a dark room, or shield the phone\'s screen. And turn up the brightness.

Software damage solution

There are dozens of software causes. Let\'s take a look at the most common ones.

Black screen after starting an app

Wait a few minutes. Some apps can take a long time to start. If the screen is still black, try closing the app. Press the Home button on your phone.

Are you using the gesture control feature? Then swipe down from the centre of the screen. If the app has been closed and the screen is working again, do not start it again.

Viruses

The general algorithm for dealing with viruses:

Press and hold the power button on the mobile phone.
When the menu appears, press and hold "Power Off" for a few seconds.
After the notification to switch to safe mode, press "OK".
Turn on the phone in safe mode.
Then there will be a screen. If the screen works, reset the phone to factory settings. This is guaranteed to remove all viruses.

If the screen does not work, connect the phone to the computer with a USB cable. Hopefully, USB debugging is enabled by default. If the computer explorer has seen the connected device, run any antivirus app, scan the phone for viruses and then delete it. If Explorer does not show your phone, take it to the service centre.

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