There is no reason to turn on the phone after turning it off

Turn your phone's network on, turn it off, and turn it back on.

If your phone has no signal or you see an emergency call prompt on your screen, we recommend that you do it

2.If it is a dual-SIM phone, please check whether the SIM card is activated: Settings - SIM Manager - SIM1 SIM2 - Click the SIM card icon - slide to turn on (the operation mode may be slightly different for different models of mobile phones).

3.If there is still no signal, it is recommended to turn off the SIM card and remove it, wipe the SIM card chip with an eraser, and then reinstall it.

4.If it doesn't work, try to change to another location to rule out whether it is caused by poor signal coverage in your location.

5.Try to change the network mode to 3G or 2G (do not select the auto-connect mode). Note: Some machines do not support changing the network mode.

6.Try to change another SIM card.

7.Update your phone's system version: Settings - About Phone (About Device) - Manual Update Automatic Update (Software Update System Update - Update). Note: Please back up the data (contacts, messages, **, etc.) in your device before upgrading.

If there is still no signal or emergency call is displayed after the above operations, please bring the purchase receipt, warranty card and device to the Samsung service center for inspection.

It may be that the card slot** is in poor contact Open the back shell and press 2 times is not a big problem.

Reason for automatic shutdown of the computer:

1.Poor heat dissipation, power supply failure, and motherboard dust failure may cause the computer to automatically shut down or automatically restart repeatedly. (Reboot is an important feature: sometimes it shuts down, sometimes it restarts).

2.When the core components of the system are damaged, the running computer may automatically shut down. Kingsoft security experts are here to provide you with special tools and system repair tools, please click Fast**.

3.In the running software, there are some software with the option to shut down when the task is completed, and the user may not have noticed and turned these switches on.

These software are more common, such as Thunderbolt, Express, anti-virus software, BT**, **** and so on. In the software settings, there is an action that automatically shuts down after completing a certain task. But generally the default setting is off.

The purpose is to automatically shut down the computer when a task is completed when a task is running a more time-consuming operation.

4.Other hardware reasons.

Mine is like this occasionally, you can brush the machine again.