Iphone 5S, no IMEI, no modem firmware

There are no user serviceable components in an iPhone, nor does Apple sell

replacement parts. By allowing an unauthorized 3rd party to work on your iPhone,

you have voided your warranty and are no longer eligible for a reduced price

Out of Warranty replacement.

Lack of IMEI and/or blank modem are usually the result of failed attempts to hack

the iPhone.

Hi there, i faced this problem on my iPhone 5s with iOS 10.2 so it kept searching for signal even when the simcard was taken out and also noticed a blank Modern Firmware on the device, anyways i came to a thread that suggested an update that would fix the no signal "searching.." problem.

So i backed up the device and updated to iOS 10.2.1 via itunes on my macbook and voila! after the update the service came back!

i noticed when the phone was being updated that a new firmware was made for the phone (i guess this was what enables the phones cellular function) and the "searching..." was gone and back to carrier signal.

Hope this is helpful 🙂

I would take it in for service

That's symptomatic of a phone that has been hacked or jailbroken. It's a critical failure and can not be fixed. Recycle it and buy a new phone.