Why mobile phone SD card is unavailable
First, you need to find out whether the problem is the SD card or the mobile phone. If the problem is the SD card, change the SD card. If it is a mobile phone problem, you should first save the important information of the mobile phone, then lattice machine (factory mobile phone), and then try again. If it still cannot be solved, we recommend that you flash the machine. If it doesn't, you will go to the Internet to find the flash machine tutorial for your mobile phone. It will generally be very detailed.
What if the mobile phone SD card is unavailable?
1) first, when inserting an SD card, we need to know the maximum number of GB of memory supported by the mobile phone. Many friends like to download the video to the mobile phone, so the SD card with relatively large memory will be inserted, however, if the phone does not support such a large amount of memory, it will display an error!
2) If the SD card is unavailable on the mobile phone, disable the mobile phone first, and then pull out the SD card to see if it is SD shift, if the SD card is installed at an offset, the SD card may become unavailable.
3) In addition, if the SD card is unavailable, we can pull out the SD card to see if there is dust on the chip. If yes, clear the SD card and insert it for use.
4) If the Android phone shows that the SD card is not available, it may be because the SD card data is damaged. Insert the SD card into your computer and format it again.
5) If none of the above methods can solve this problem, it may be because of a problem with your SD card. Just try another one.
6) If the card is put on another person's mobile phone, it will prove that there is a problem with your mobile phone contact. Check it. If not, format the card. Otherwise, change the card.
Summary
Occasionally, the memory card may be incompatible with the mobile phone. Try to format the memory card on the computer and change the FAT32 format. If not, try replacing the memory card. If it is useful, it indicates the memory card problem.
It may be because the re browser does not mount the read/write memory card. Go to the sdcard and root directory and check whether the read/write is mounted or read-only in the upper right corner. If the read-only mode is read-only, you can simply mount the read/write mode.