Bad baseband or modem?
I did a housing swap on an iPhone 7 and LTE would be acting weird. Like right now I did a dfu restore and it’s saying no service when there’s no SIM card installed. I’ve tried to change the antenna that sticks to the speaker and that didn’t fix it. Also LTE turns off when I’m not using the phone but sometimes when I unlock it the signal comes back, weird. I’m stumped as I know how to fix phones but I’ve never seen this before. It also says iccid unknown.