Apple is adding software to ios updates that will detect aftermarket batteries, screens, possibly other components. There is no way to fight this right now. The only answer is to find used Apple parts. Any repair shops using aftermarket batteries and screens could be bit hard later when all your customers end up with boot looping iphones. If you then try to go to the Apple store and have them install a real Apple screen, they won’t do it. Any aftermarket parts installed will prevent them from doing any repairs at all.
This is the classic error code for baseband issue now recalled by Apple on iphone 7 Model A1660 only. You need to take it to a real Apple store and they will send to Apple to determine replacement eligibility. https://www.apple.com/support/iphone-7-no-service/
1. Plug iphone USB cable into computer. 2. Open device manager. 3. In the USB section at bottom find Apple device. 4. Right click the device. 5. Click uninstall device. 6. Check box to remove software. 7. Unplug USB and replug into computer. 8. Box will appear asking what to do with this device. Quickly click that box. 9. Another box will open. 10. Select ' open explorer box' That is now the default for this iphone
There are a few techs on ebay who repair this problem. It requires micro soldering of one to 3 components. You must disconnect power from motherboard before you pull off the LCD connector. When reassembling, you screw down motherboard last. Otherwise you sent s spark through the circuit.