What should I do if my phone can t use 4G, what happens if my phone can t use 4G

Apple has no signal or is searching in general, the problem is actually very simple, first look at the time and date of the mobile phone is correct, adjust the time and date, if there is still no signal, and then repeatedly switch on and off the airplane mode 2 times.

It can generally be solved.

If none of the above can be solved, then you have to consider whether there is a problem with the hardware of the phone.

The most problematic problem with Apple's mobile phone is definitely the baseband.

Abnormal occurrence of three no faults (no signal, no wifi, no serial number), some appear after falling, some appear after flashing, of course, there are also normal use of three no faults, especially bought on the Internet, three no faults appear more and more frequently. The second is that there are users who lock the machine and originally used the card, and the baseband is raised and the card cannot be unlocked again, in this case, it can only be unlocked by replacing the baseband of the mobile phone by changing the baseband or lowering the baseband. There are also many faults with no signal or poor signal.

I have repaired no less than 1,000 Apple mobile phones, in my actual maintenance of Apple mobile phone statistics, repair these three faults may account for more than 70%, I believe that anyone who has been in contact with the repair of Apple has a deep experience.

If you are using a Huawei mobile phone, there are many reasons why the mobile phone does not have a 4G signal and only a 2G signal, please follow the following methods to troubleshoot:

1.If you have no 4G signal on the primary SIM card when you are using dual SIM, make sure that the supplementary SIM card is receiving MMS.

If you encounter a problem when the supplementary card receives SMS and MMS messages, the main card will display 2G:

1) You can enter the information interface, click on three dots or four dots, enter More > Settings > Advanced or Settings > Advanced, and then set Auto MMS to Off.

2) If your mobile phone supports dual VoLTE dual pass, it is recommended that you enable the Dual SIM VoLTE function: in the VoLTE network coverage area, when the dual HD icon is displayed in the status bar of the mobile phone, two cards can work at the same time.

2.Please make sure the 4G switch is enabled.

1) When installing a single SIM: Please swipe down from the top of the phone screen, open the shortcut menu, press and hold the mobile data icon, enter the settings interface, turn on Enable 4G or select 4G 3G 2G in network mode to automatically select.

3.Please move your current location.

You can consult the network coverage of the local operator, or observe the mobile phone network conditions using the same operator's SIM card nearby, if there is no 4G network in the same situation, it is generally caused by the poor and unstable 4G network coverage of the local operator, it is recommended that you try after moving to other places.

4.Please restart your phone or switch on and off airplane mode.

The special configuration of some networks may cause your phone to be unable to return to the 4G network for a short period of time, but it can be restored after restarting the phone or turning on the airplane mode.

5.Please reset the APN

Incorrect APN settings will affect the normal use of the network.

It is recommended that you open Settings, enter APN in the search bar at the top, click Access Point Name (APN) to jump to the mobile data settings interface, click the Access Point Name (APN) again, then click the three dots in the upper right corner, and select Reset to Default Settings.

6.Please reset your network settings.

7.Please remove the SIM card.

1) If your mobile phone card is manually cut card, it may affect the signal reading due to non-standard shape and poor contact, it is recommended that you bring your personal ID card to the operator's business office to apply for a standard mobile phone card.

2) Dirty or oxidized SIM cards will also affect the reading of signals, so it is recommended that you keep the SIM card clean.

8.It is recommended to update to the latest system version in a timely manner.

If your phone still only has a 2G signal, contact Huawei Consumer Service** (950800), back up your data in advance (third-party apps such as QQ and WeChat need to be backed up separately), and bring your purchase voucher to a nearby Huawei Customer Service Center.

Make an appointment for service. Boarding service.

Repair spare parts** inquiry.

Taking Huawei P40 and EMUI10 systems as examples, the specific reasons why the mobile phone cannot use 4G are as follows:

1. If the status bar above the mobile phone does not display the 4G signal or the mobile phone itself cannot use the 4G network, it may be a problem with the SIM card, if the SIM card is cut and in arrears, or the 4G service is not opened, the mobile phone will not be able to use the 4G network. If the SIM card is a special SIM card, then some special SIM will have restrictions on the use of the 4G network, for example, Unicom's special traffic card needs to manually modify the APN before it can be used, and the telecom special traffic card can only be used on the mobile phone that inserts this card for the first time4G, different SIM cards have different ways to use, it is recommended to contact the operator of the card to ask how to use it.

2. The problem of the mobile phone case, if you are using a metal mobile phone case, you can first take off the mobile phone case and try to reconnect, if the signal connection is successful, then part of the metal in the metal mobile phone case shields the signal, causing signal interference. It is recommended to replace the phone case with a new one.

This answer applies to most brands of mobile phone models such as Apple, Huawei, Xiaomi, OPPO, etc.

If you want to use the China Unicom 4G network, you need to meet the following conditions:

Use China Unicom 4G** or have opened 4G network function;

The mobile terminal supports China Unicom 4G network;

The location has a 4G network covering China Unicom;

The number card is a USIM card.

You can check whether the above conditions are met, and you can only use the 4G network after you meet them, if you still can't use the 4G network after eliminating them, it is recommended to consult the local Unicom customer service to check whether the base station facilities are faulty.

Look at your 4G network.

Your SIM card must also be enabled for 4G.

See if your card is a 4G card.

A 4G card is required, and the operator's 4G network is already covered in your area.

If the card is 4G, sometimes you have to consult customer service yourself to enjoy the 4G network.

If you are using a vivo mobile phone, the troubleshooting method for not being able to use the 4G network is as follows:

1. Enter Settings - Mobile Network (Dual SIM and Mobile Network) - Mobile Unicom Telecom - Network Mode, 4G Mobile Phone Selection: 4G (Priority) 3G 2G, 5G Mobile Phone Selection: 5G (Priority) 4G 3G 2G

Note: If you can't see the network mode through the above methods, you can enter * * to view the network mode through the dial pad.

2. Confirm whether to use third-party magnetic or metal accessories.

Please check whether you use metal protective shells, magnetic protective shells, magnetic brackets and other accessories, metal and magnetic materials are easy to interfere with signal reception, it is recommended that you remove the accessories to view.

3. Check whether the current environment covers the operator's network.

You can observe the mobile phone signals of the same operator's network in the surrounding area, and if there is no 4G network, it is caused by the operator's imperfect 4G network coverage. In a closed indoor environment (e.g., basement, elevator, etc.) or in a relatively remote area, the operator's network may not be fully covered.

4. Restart your phone or switch on airplane mode.

In some areas, the network configuration may cause the phone to fail to return to the 4G network in a short period of time, so you can restart the phone or turn on the airplane mode to try.

5. Check the SIM card and perform cross-card verification.

Observe whether there is dirt or oxidation on the metal surface of the SIM card, and check it after cleaning. If you use a tailor-made SIM card, it is recommended to replace it with a standard SIM card. Install the SIM card to another device, or install another SIM card to your mobile phone for comparison and testing to determine whether it is a SIM card failure.

If it is a SIM card reason, it is recommended that you go to the operator's office to replace the card.

6. Upgrade the system or reset the network settings.

Please upgrade your phone to the latest version, if your phone is already the latest version, it is recommended that you go to Settings - System Management - Backup & Reset - Reset Network Settings - Mobile Unicom Telecom - Reset Settings, and then use it to view.

Note: Resetting network settings resets Wi-Fi, mobile data, and Bluetooth connection records.

7. Service center testing.

If the above methods fail to solve your problem, please back up your mobile phone data in advance, bring your mobile phone and purchase voucher to the vivo customer service center for testing, pay attention to WeChat***"vivo" or "vivo customer service" to inquire about the service center address**, it is recommended to contact before going to ensure that there is a staff to receive you and then go over, so as to avoid delaying your precious time and letting you run in vain.

If you can't use the 4G network, Samsung phones can troubleshoot and deal with it in the following ways:

1.Check whether the SIM card supports 4G services.

2.Whether to select 4G network mode: Settings - Connection - Mobile Network - Network Mode: SIM1, SIM2, 4G, 3G, 2G (Auto Connect) or 3G 2G (Auto Connect).

Note: When two cards are inserted into China Unicom mobile card: 3G or 4G network cannot be used at the same time, if one card is set to 4G 3G 2G (auto-connection) or 3G 2G (auto-connection), then the other card will automatically become 2G network only.

3.Check if your area is covered by 4G networks and try to move to another location.

4.Shut down, restart, or try to change the card.

5.If it doesn't work, it is recommended to back up the data in your phone (contacts, messages, **, etc.) and try to restore factory settings;

If the problem still exists, please bring the purchase invoice, repair card and machine to the service center, and the professional after-sales engineer will help test it.

1. The 4G network coverage in the area is not fully covered or the 4G network signal is not good, in this case, you can contact customer service to ask about the network coverage or try to see if there is a signal elsewhere.

2. The mobile phone card is faulty, resulting in the mobile phone can not be connected to the 4G network, in this case, you can change someone else's card to try, or put your own card on someone else's mobile phone to try.

3. There may be problems with network settings or mobile phone settings, in this case, you can restart the mobile phone or restore the network settings.

4. The mobile phone system may fail, in this case, you can try to flash the machine, or send it directly to the after-sales service for testing and maintenance.

Taking Huawei mobile phones as an example, the reasons why it can't use 4G and the solutions are:

1. If there is no 4G signal, turn on the airplane mode switch, and then turn off the airplane mode switch to give it a try;

2. The mobile phone has no phone bill, and the network can be restored after recharging the phone bill;

3. If there is no traffic, you can re-set the ** traffic or turn off the traffic monitoring and then re-open the network.

Huawei Technologies **** is headquartered at Huawei Base in Bantian, Longgang District, Shenzhen, Guangdong Province, China. Huawei was officially incorporated in 1987 in Shenzhen, China. In 2007, the contracted sales were 16 billion US dollars, including overseas sales of 11.5 billion US dollars, and it was the first in China's domestic electronics industry in terms of profit and tax payment that year.

By the end of 2008, Huawei had covered more than 100 countries and regions in the international market, and 45 of the world's top 50 telecom operators had used Huawei's products and services. Huawei's products and solutions have been used in more than 150 countries around the world, serving 45 of the world's top 50 carriers and 1.3 percent of the world's population.