Check as follows:
1, forced restart, unstable system resources occupied by some software during operation,
Restart can be solved, of course, this only limits the situation of rare crashes.
2. If it still doesn't work, cclean, slim down the phone.
2. If it is still the same, kill the virus and restore the factory settings of the mobile phone.
3, if still, brush the machine again.
4. If this is still the case, it is a motherboard problem, and it is recommended to send it for repair after sale.