Nowadays the mobile phone signal is getting better and better, generally it will not affect normal calls and Internet access. However, we may still encounter weak signal or no signal that affect our phone using experience. Here are some reasons why the iPhone has weak or no signal.1.The surrounding network is poor.Sometimes the mobile phone will be in an out-of-service state due to the poor network in the surrounding environment. At this time, the mobile phone will have no signal and no service. Moving to another place with a good network can solve this problem.2.Network settings problem.After using the iPhone for a long time, the phone may not be able to connect to the network due to some reasons of the system itself. You can restore the network settings and restore to the default factory settings to solve the problem of no service, or restart the phone to solve the problem.3.SIM card problem.If the mobile phone cannot connect to network, there may be a problem with the SIM card. We can take out the SIM card and check whether it is damaged, or find another SIM card and insert it into the iPhone to check if the SIM card is broken. If it still has no signal, then it can be denied that it is the reason of SIM card.4.System software problems.There may be loopholes in the iOS system of iPhone, these loopholes may sometimes cause the phone to not be able to search for network and thus show no service. You can update your phone's system to the latest version, which can usually solves this problem.5.Mobile phone hardware problems.If the above methods can't solve no signal problem, it is likely to be a problem of hardware. The SIM card slot, signal antenna, radio frequency chip, baseband chip, and even the welding of the mainboard will affect the signal. Specific hardware problems need professional maintenance personnel to judge, then it is best to go to Apple's after-sales service or other iPhone repair store. About OriwhizORIWHIZ is a mobile phone LCD/OLED screen and other phone spare parts' manufacturer（factory）,we offer OEM and ODM service to customers all over the world.Our products have ISO9001,CE,FCC,ROSH certificate.All of our products are manufactured by brand new materials and 100% quality test before shipping.We promise our best quality products will be delivered to our clients on time.We have professional customer service and welcome inquiry any time. Our main products include:iPhone LCD,iPhone Charging Port,iPhone Front Camera,iPhone Back Camera,iPhone ear speaker,iPhone Battery,etc.Not only iPhone related products,we also have Samsung,Oppo,Vivo,etc.