Oppo A31 (2020) Unrecognized SIM Card Error [Fix]

Here is How To Fix Oppo A31 (2020) SIM card not detected error? How To Fix Oppo A31 (2020) SIM card not recognized? Fix Oppo A31 (2020) SIM card not inserted error prompts.

Have you just bought or using Oppo A31 (2020) for a long time, it might be discouraging if some error prompts appear on your screen? Many times messages such as “SIM card not recognized” might be disturbing you. Occasionally the Oppo A31 (2020) does not recognize the SIM card and displays this message. Fortunately, there are many tips to fix this issue. We will therefore provide tips and tricks in this tutorial, the stuff provided will give information to confirm so that the SIM card is recognized on your Oppo A31 (2020).

About Oppo

Oppo A31 (2020) Unrecognized SIM Card Error [Fix]

OPPO Electronics Corp. is an electronics manufacturer based in Guangdong, China. Known for its smartphones, the company also makes MP3 players, portable media players, LCD-TVs, and DVD/Blu-ray players. It was founded in 2004. The company is also a smartphone maker. It has launched a whole range of Android-powered smartphones.

More information

What Is an “Invalid SIM Card” Error?

Invalid SIM card error means that either there is no SIM card on phone or it may be due to a faulty connection or it is loose. Some connection between your SIM card and its tray must have some fault.

Therefore, you should find out the source which is leading you to see such an error message on your Oppo A31 (2020)’s screen.

Reasons Behind “Invalid SIM Card” Error On Phone

Have you ever thought about why such an error comes on the screen of your device?

There are two locks that can lead to such error messages on your device. The two locks are given below.

Network lock: It means that you cannot use any other SIM card other than the one you have got with the phone itself. The lock is not done by your smartphone manufacturer but’s from your network operator. The lock can be removed after going against their terms, there are a huge amount of guides available on the web to unlock your phone.

Region lock: This lock is done by your smartphone manufacturers. It means that your SIM card will not work on your Oppo A31 (2020) if it is from another specific region or country. There are many reasons why region locking is done, you can read about that on Wikipedia.

Oppo A31 (2020): Unrecognized SIM card error fix?

Oppo A31 (2020) Unrecognized SIM Card Error [Fix]

In the event when a SIM card is not detected by your smartphone. There is a list of tips that can be helpful to determine the source of the problem to further guide us to fix the issue.

Reboot or Soft Reset your Device

Here is the guide to soft reset Oppo A31 (2020)

There are some times when the device simply failed to detect the SIM card due to software glitches and minor errors. This kind of occurrence can be easily fixed with a simple soft reset or reboot to your device. If this is the first time you got this message then you should first give a try to rebooting your phone.

To perform a soft reset or reboot your device follow the instructions provided below.

  1. Press and hold Power and Volume Down buttons simultaneously for about 8 to 16 seconds.
  2. Release both the buttons when the phone starts restarting if the key combination is not working try simply pressing and holding the Power button.

Note: It is a simple restart nontechnical process, and will not hard your device’s data.

Cleaning the SIM Card

Cleaning is the initial step and before taking any further steps we’ll try to fix this issue by simply cleaning the SIM card. Mostly the SIM card is not able to be detected as the dirt partially prevents the contact between the SIM card and the phone. To clean it, pass a small dab of cloth over it and check if it is not damaged.

Check the location of the SIM card it may need to be removed and reinstalled

There may be an issue sourced from the location of the SIM card. It often happens that small metal plugs that normally have to come in contact with the SIM card are a little relaxed. When this is the case, this prevents your Oppo A31 (2020) from reading the SIM card. To fix this issue, you just need to thicken the SIM a little by gluing 1 or two pieces of tape at the bac

Switch to a different network mode

Changing the network mode on your Oppo A31 (2020) can also help if something is wrong with the current network mode in use. Don’t forget to test your phone after switching to a network mode to see if the error “SIM can’t be detected” is gone or not with the current network mode selected. Follow these steps to change network mode on your Oppo A31 (2020)

  1. Go to Settings.
  2. Click Connections.
  3. Select Mobile networks.
  4. Click Network mode.
  5. Click to select another network mode like Auto, LTE, 3G, or 2G network.
  6. Choosing Auto mode lets your device find the best network mode available to use but there are instances when this mode is not applicable depending on the location and network service availability.

After you switching to the different network mode remember to give a soft reset (reboot) to your phone. If the method has not fixed the sim card not recognized error on your phone then give a try to another option.

Test your SIM card on a different Smartphone

If the SIM card is facing issues it must be tested on other devices. If the issue has come from the card itself it should not be working on other phones. When it is not recognized in other phones then you can get a modified one from your network provider.

Try another SIM card on your Phone

If the methods provided above are not able to fix or find the issue in your SIM card or phone then you should try using some other SIM card on your device. In the event, another SIM card is functioning on your Oppo A31 (2020) then the issue is being in your current SIM card. Otherwise, the mobile phone may be compatible with your SIM card.

Check that your Oppo A31 (2020) is not Simlocker

When you have tried many SIM cards on the Oppo Xperia C3 and none are recognized then your phone should be Simlocker. This implies that your phone will recognize simply the SIM card of a certain operator. In this case, you have to unlock it. Search “How To Unlock Simlocker in Oppo A31 (2020)” on Google you’ll get a bunch of sites providing information.

Check that the problem will not be sourced from the ROM installed on the Oppo A31 (2020)

This part is mainly for the people who have rooted your Oppo A31 (2020) to install a Custom ROM. The event which has been currently performed by you be aware that unrecognized SIM card issue is quite common after setting up fresh ROMs. We advise that you reinstall an original or Stock ROM and re-test it. First, try a hard reset on your Oppo device, if not fixed then reinstall the stock ROM. Read the guide below to factory reset your phone.

Hard Reset your Oppo A31 (2020)

Hard Reset is the process of removing all files and data from your phone to fix some errors which can’t be fixed. After performing this process all data will be wiped from your devices such as personal information along with all the errors and corrupt files. So make your you have taken a complete backup of your device. To complete this master reset process take note of your Oppo credentials as it activates the Anti-theft feature on your device.

First, Create a Backup of your device

To back up your data, go to Apps-> Settings-> Cloud and accounts-> Backup and restore. Then select the option to Back up my data or Automatic restore.

To Factory Reset your Oppo A31 (2020)

Go to Settings-> General management-> Reset-> Factory data reset-> Reset-> then tap Delete All to confirm. If prompted, enter your credentials or verify your Oppo account and password to proceed with the reset process

If the SIM card error still persists then you should consider the last option of replacing your SIM card.

Finally, If No Methods are working?

If followed all the steps then we advise you to bring your Oppo A31 (2020) and the SIM card back to one of your operator’s shops.

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