What to do if there is no signal after Xiaomi Mi 2A update V5

Reasons and solutions for mobile phone no signal:

There is no signal on the mobile phone Situation 1:

See if your current location is out of the signal blind spot, the blind spot includes outside the network coverage area, such as workshops, factories, suburbs, rural areas and other places where network communication facilities have not yet been built, as well as urban signal mobile phones are shielded and blocked signal can not be covered, such as office buildings, bar rooms, elevators, underground places, buildings and other places.

Solution: Step out of a field where there may be no signal and dial ** in a wide area.

There is no signal on the mobile phone Situation 2:

If there is no problem with the location, it may be caused by interference facilities, and the mobile phone receives the signal through the propagation of electromagnetic waves, so the base station establishes a connection between the transmission of radio waves and the mobile phone, so as to achieve the purpose of voice call. Interference from electromagnetic waves can affect mobile phone signals, which usually occurs in the test room.

Solution: Find the surrounding signal interference equipment, turn it off or remove it.

There is no signal on the mobile phone Situation 3:

Temporary glitches may occur when the network is particularly busy, which can also have an impact on the mobile phone signal. For example, in the bustling business district, there will often be a situation where you can't get out, and others can't get in, especially during peak hours, and there are often delays in commuting and holidays.

Solution: Avoid busy business districts, during peak hours, the signal condition will automatically improve.

There is no signal on the mobile phone Situation 4:

If the mobile phone does not have a signal caused by external factors, it is likely that the battery voltage is unstable, the power supply of the receiving circuit is insufficient, the voltage is fluctuating, and the signal reception cannot be stabilized. In this way, the mobile phone will not be able to access the Internet, and even ** will not be able to call.

Solution: Change to a higher quality **, and the signal problem will be fixed.

There is no signal on the mobile phone Situation 5:

The loss of the baseband serial number, that is, the "radio" in the mobile phone, the radio is responsible for the communication function of the PPC as a mobile phone function, once the software application layer is lost or the data is destroyed, it will not be able to connect to the network and make calls**.

Solution: Re-flash the ROM of the corresponding model, or you can enter the radio of the model separately.

Settings, Mobile Network, Select Carrier, Change to Manual, Change to Automatic when there is a signal.

It is recommended that you check your signal value in the ** mobile phone information on the dial interface, and the signal strength is best at -50 -80dBm.

If your Mi Phone 2A has no signal, we recommend that you follow the steps below to try to solve the problem

1.Whether the SIM card is inserted correctly, and try to re-insert and unplug it;

2.Whether the wrong SIM card is inserted, such as the standard version inserting the telecom SIM card, such as the telecom contract machine inserting the mobile card, etc.;

3.Enter "**" on the dial-up interface to enter the hardware detection mode, turn on the SIM card for testing, if the SIM status is normal, go to step 5, if the status is unknown, go to step 4;

4.Try to replace a different SIM card, if the status is still unknown during hardware detection, it is recommended to go to the repair point for testing; If the detection status is normal, it is recommended to go to the operator to replace a SIM card (it is not ruled out that the SIM card is due to aging);

5.Whether the network type is correct (China Unicom selects 3G priority, China Mobile selects 2G only, and China Telecom selects automatic), the operator selects whether it is automatic, and you can enter * * on the dial-up interface, and select the mobile phone information to manually set the preferred network type after entering;

6.Whether the signal in your area is normal, it is recommended that you check whether other mobile phones on the same network have signals;

7.Upgrade to the latest system version and try again.

1. There is no signal or the signal is relatively poor, mainly because the signal will be affected by various factors such as terrain, landform, and high-rise buildings in the process of propagation, such as the current location is in a relatively closed place, and the signal may be affected.

2. If the mobile phone signal of other China Unicom users is normal, the following methods can be used to troubleshoot:

Method 1] Turn on airplane mode, then turn off or restart your phone and try again.

Method 2] Test of changing the phone card to change the mobile phone card to the mobile phone of a family member or friend and try again.

Feedback, we will check and deal with it as soon as possible.

Hi! Please apply for after-sales service in your order.

A more detailed description of the problem will help netizens understand the troubles you are encountering and help you solve the problem more accurately. Thank you for supporting Xiaomi phones!

The Internet said that the back cover should be removed and isolated from the back cover with tape, can you try it?

Did you have a bank card or ID card inserted in your phone case? Take it out and you'll be fine.

There are several reasons for this:

1. Take out the card and put it into another mobile phone, and the information is normal. If there is no problem with the signal, it means that there is no problem with the SIM card.

2. After backing up the mobile phone system, the fault phenomenon is still the same.

3. Restore the factory settings, and the fault phenomenon is still the same.

8. Sometimes there will be a weak signal after restarting, sometimes you can dial **, sometimes the weak signal can't be dialed out.

9. Repair at a nearby repair shop, and was told that the hardware test is normal, and I don't know what the reason is.

Take out the card first and then put it back on, if there is still no signal, then turn it off, and then turn it on and try it. If there is still no signal in this way, it should be a problem with the motherboard of the mobile phone, and you should take it to a Xiaomi repair shop to test 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.

There is no workaround for the signal.

1. The problem of the operator, in general, this possibility is relatively large. In this case, it will be better to call ** to the operator's customer service complaint.

2. The mobile phone does not receive a good signal, and this possibility is generally very small. Generally, it will not appear, and if the mobile phone has been used for a long time, it is easy to appear this possibility. Try to replace other mobile phones, if the signal of other mobile phones is normal, it means that it is a problem with the mobile phone, and you can take the mobile phone to the after-sales point for maintenance.

3. There is no mobile signal coverage in the area, so it will also lead to no signal. Go to a place where there is a signal and use it, and you can have a signal.

Try shutting down for a long time yourself, if it doesn't work, take it to Xiaomi Home and ask.

It was a signal issue, which I had when I was in the mountains, and the rest of the place was fine.

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 "WCDMA Preferred" in the mobile phone information (**) 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 center for repair and inspection.