My Xiaomi Mi 4 always doesn t get a signal

It is recommended that you check it out by following the following methods:

1. Whether the SIM card is inserted correctly, different models support different 3G standards, and the mismatch has an impact;

2. Whether the network type is correct, whether the operator selects whether it is automatic, and it is recommended that 3G be preferred;

3. Enter * * in the dialing interface to detect whether the SIM card is working normally;

4. Try to change a different SIM card to eliminate the SIM card problem;

5. Whether there is no signal in the area, 4G signal coverage is incomplete, it is recommended to turn off the 4G observation signal;

6. Back up the data, flash to the latest system version and try again;

7. If the above methods still can't solve the problem, send it to the maintenance point for maintenance and testing.

Hi! It is recommended that you check it out by following the following methods:

Whether the SIM card is inserted correctly.

Whether the wrong SIM card is inserted, such as the standard version inserts the telecom SIM card, etc.

Go to Hardware Detection to see if the SIM card is working properly (enter * * on the dial screen). If the SIM status is normal, go to step 5, or if the status is unknown, go to step 4.

Try to replace a different SIM card, if the status is still unknown during hardware testing, it is recommended to go to the repair point for testing; If the detection status is normal, it is recommended to go to the carrier to replace a SIM card (the SIM card may be aging).

Whether the network type is correct and whether the carrier selects Automatic. (China Unicom selects 3G priority, mobile selects only 2G, and China Telecom selects automatic).

If the network type of the non-telecom mobile phone is CDMA automatic, you need to change the network type to the mobile phone information (**)."wcdma preferred"to solve the problem.

Whether there is no signal in the area. You need to check whether other mobile phones on the same network have signals.

Back up your data, flash to the latest system version and try again.

If the above methods still do not help you solve the problem, please go to your nearest repair point for repair inspection.

The reason why Xiaomi phones have no signal or cannot receive a signal is because the signal will be affected by various factors such as terrain, landform, and tall buildings during transmission, and if you are in a relatively closed place, the signal will be affected. Here's how to deal with it:

1.Turn the phone back on and off and try again;

2.Swap the SIM card to a family member's or friend's phone and try again;

3.Check to see if other Unicom users around you have a signal;

If there is no signal, you can contact human customer service for feedback.

If there is no signal on the phone, it may be a signal problem, or it may be a problem with the phone card, or it may be a problem with the phone system.

If the phone has no signal, no service, and does not read the SIM card, it is recommended to test it according to the following methods:

1.You can first open the phone's settings - about the phone, check whether the baseband version, IMEI, and serial number are unknown, if you find it unknown, it is recommended to send it for repair;

2.Go to "Settings--Network--Network Mode" and check whether the 2G 3G 4G setting mode matches the type of SIM card used;

3.Go to "Settings - Network - Network Operator", check Automatic, observe whether the service is restored, if there is no service recovery, restart to observe whether it is restored; If you recover after restarting, it may be caused by "baseband and firmware", and you can flash the firmware and baseband maintenance again.

4.Turn off the phone, pull out the SIM card slot, confirm whether the SIM card contact points are damaged or dirty, wipe it clean with a clean cotton cloth and insert the phone again to confirm whether it is restored;

5.Replace SIM card test.

Note: If the fault persists, it is recommended to send it for repair.

Try a different card to see if the mobile network settings in the settings are normal, or if it is not good to repair.

Xiaomi already loves to crash and have no signal, just restart it.

The reason for the bad signal is that the signal will be affected by various factors such as terrain, landform, and high-rise buildings in the process of propagation

1. Turn the phone on and off again;

2. Swap the SIM card to a family member's or friend's phone and try again;

3. Check whether there is a signal from other Unicom users around;

If the above situation has not been resolved, it is recommended to contact the manual customer service of the place where you belong for processing.

If Xiaomi is not good, change to Apple.

In fact, the signal is not necessarily a problem with the mobile phone itself, and there will be no signal if the network has blind spots in some places, which is related to network coverage.

You can detect it like this, plug your mobile phone card into other mobile phones to see the signal, if the signal is not good, you can **contact the operator of your **card** and let them solve it. If it is really a mobile phone problem, negotiate with the manufacturer or seller.

If you don't have a signal on your phone, it is recommended that you:

Whether the correct SIM card is inserted and try to replug it;

2.Whether the wrong SIM card is inserted, such as a mobile card inserted into a telecom contract machine, etc.;

3.Enter * * in the dial-up interface to enter the hardware detection mode, if the status is abnormal, try to change a SIM card;

4.Go to Settings --- Mobile Network--- select the corresponding SIM card information--- select the network type--- select "4G Network First", and select the operator--- turn on "Automatic Selection".

5.If there is no problem with the SIM card and related settings, please try to do a factory reset. If the problem persists, it is recommended to go to the repair point for testing.

How to deal with SIM card not recognized by mobile phone:

1. Please confirm whether the SIM card type is correct according to the mobile phone model. An incorrect SIM card can damage the card tray and card slot or even fail to be removed;

2. Please make sure to use a standard SIM card. Do not use a non-standard SIM card or cut the card by yourself, cutting the card can easily cause the SIM card to be unable to recognize or damage the mobile phone, it is recommended to go to the business hall to change the original standard SIM card;

3. Please confirm whether the card is placed correctly. Whether the notch of the SIM card corresponds to the card slot;

4. Please confirm whether the surface of the SIM card is dirty. If the SIM card has been used for a long time, you can wipe the surface of the chip with alcohol, or go to the business office to replace the original standard SIM card. If the SIM card is used for a long time, the metal surface is easy to be oxidized, which is easy to cause probabilistic card recognition;

5. Do not plug or unplug the SIM card when the device is turned on. After inserting the SIM card, please restart your phone and try;

6. If the problem still exists, please back up the data in advance and bring the purchase invoice to the after-sales service point for maintenance.

1. It may be that there is no signal coverage near the mobile phone, resulting in a sudden lack of signal on the mobile phone.

2. It may also be a problem with the mobile phone card, which may lead to no signal in the bureau, so you can change the mobile phone card to test it.

3. Or if there is a problem with the system of the mobile phone, you can restart the mobile phone to try; If necessary, you can reset the system or upgrade the system to resolve the issue.

4. If none of the above methods can be solved, it may be caused by the hardware failure of the mobile phone, such as baseband failure, RF antenna failure, etc., and it is necessary to contact Xiaomi's after-sales service to repair the mobile phone to solve it.

Hi! Please back up your data, enter the recovery clear button to pretend to be all data (turn off, press and hold the volume on + turn on the machine key to enter recovery).