The sim card of Xiaomi 3 mobile phone cannot be read. What should I do?

Check whether it's a SIM card problem or a mobile phone problem.

1, the simplest reason, check whether the sim card is inserted backwards. If it is inserted backwards, the phone can't read the sim card, so you need to insert the sim card in the right way.

2. Change to a normal mobile phone and put the sim card on another normal mobile phone to see if it can be recognized. If other normal mobile phones can't recognize this sim card, it means that this sim card is broken.

3. Take a sim card that can be used normally in someone else's mobile phone and put it on the mobile phone that can't recognize the sim card. If the normal sim card cannot be recognized, then some parts of the mobile phone are broken, which may be a hardware problem or a software problem.

4. Poor contact of 4.sim card. For this problem, before installing the sim card, we can gently press the metal fixing elastic piece on the sim card, then gently press it after installing the sim card, or move the sim card back and forth.

5. For some sim card slots with poor quality, if the sim card is inserted frequently, the sim card slot may be broken, so that the sim card can be recognized on the normal mobile phone, but other normal mobile phones can not be recognized on our mobile phone, so the sim card slot may be really broken, so we can only send it to repair, and then further determine the reason.

6. Don't be too nervous when the sim card can't be read. You can check the sim card of the mobile phone first to see if the card is installed incorrectly or because the SIM card is broken. Of course, it may also be because the mobile phone is broken.