What's wrong with Apple's 7plus mobile phone without service?

There are many kinds of non-service situations. First, because the service provider's signal is not good, you may be too far away, and there may be one in the city. Second, there may be something wrong with the machine. If it is authorized or unlocked, it should be no problem to restart. If there is a lock, there is generally no sim. If there is no service all the time, please check whether the location of the card sticker and sim card has changed, or the machine upgrade has caused the unlocking to be invalid.

If a signal suddenly shows no service before, then 1. Maybe your local signal is unstable or no signal. 2. The antenna in your mobile phone may be in poor contact due to falling, especially the signal problem of iPhone 14! If there is no service because you swipe your mobile phone or you just bought it, then 1. Your mobile phone is locked, so you can't use China's SIM card. 2. The quality of the mobile phone itself.

If you can't solve your problem, I suggest you take your mobile phone to Apple Customer Service Center for repair.