The coil looks okay, the symptom looks more like a baseband logic or hardware issue.
FYI this is the common procedure to resolve reception issues
If the phone is showing reception issues, try the following
Remove all external accessories to rule out 3rd party accessories that could block or even interfere with the signals
Test the reception on another known good identical phone to rule out coverage issues
Reboot/restore or upgrade the phone software to rule out potential software issues.
If none of the above works, there are probably hardware issues.
I've observed newly powered on iphones constantly display "searching" until the system clock is synchronized with apple servers and airplane mode is cycled. The baseband was stuck on wrong config data because the clock is off. reboot or just recycle the airplane mode should clear it out.
If it still doesn't work, go to settings-general-about to check the IMEI\baseband virsion\ICCID is abailable. Missing IMEI and version means that the baseband is not working, Having these but the ICCID is blank means that the SIM card is not linking with the phone. Both cases are difficult to repair