Sure (I'll do my best) :)
First, I definitely took the long route bc I figured I just needed to and am stubborn and possibly rushed through some steps and/or skipped some. I want devices fixed...drives me mad especially when I truly feel I must've overlooked something, etc. Plus I still felt the carrier (tech rep) could make other adjustments if I took the time to give good feedback, so just a head's up on the VERY lengthy explanation, etc
Step 1) Spoke with carrier rep in tech support first. We went step by step through each of the carrier settings, including all identifying info for the device. Rep made sure all info aligned.
We did basic troubleshooting as I'd done before and yep, even reset all network settings again.
One thing we did a bit different than I had done previously, was turn off data roaming - when he had me do this, the signal came up and searching ceased.
But, he still wanted me to toggle back on, so I did.
When I turned it back on, searching returned, no service. :( ....but, I had some hope now.
At this point, I didn't go into the data roaming reasoning and asking all sorts of questions. Instead, I just asked him, what if we do a fresh update in iTunes (I was on 11.2.2 already) then restore as new? Do you think it might help now? Carrier tech was on board but wasn't fully confident with guiding me through the restore process.
He contacted Apple, the two techs reviewed steps done so far, I gave feedback as needed, and after getting all info, the Apple tech stated everything seemed on point so far and felt confident with a new update & restore at this point. She explained that she was going to walk me through the update and restore, but she was going to have me complete it a bit different than the standard process. (Fine with me. Anything I could try, I was willing at this point and grateful).
She stated we were going to complete the processes in more definitive stages than what I had tried.
First - we made sure my iTunes was updated to 12.7.2. It was. We then put device in recovery mode while plugged into iTunes.
She then made sure I did a sw update ONLY.
After allowing update to process, we let phone restart. After restart, we disconnected phone from iTunes, and she had me plug phone back in (put device in recovery mode again to bring up restore prompt in iTunes).
We initiated a restore. (Sidenote) It never prompted to update, which I still expected but nope. It only began to process a restore, which the Apple tech stated is the result we want right now.
**Other: iTunes errors would pop up (think i got 3-4 spontaneous ones pop up total) but Apple tech had me close error boxes, proceed with the process, and it was as if no errors existed. They never repopulated. That was a first on iTunes and a nice one!
However, there was one restore error that did appear and couldn't be overridden by closing & continuing. She fixed this first, then had me simply start the restore process again and the error did not appear again.
Restore only completed on second try.
At this point, we unplugged and set up the device as NEW.
Restarted device
Then, they both had me go to Settings - General- About - then carrier rep stopped us and had us wait for approx 15 seconds. A carrier update popped up to prompt to update.
Carrier rep & Apple tech both asked me to go forth.
I allowed carrier update to run which didn't take long.
Restarted device again
The service on the phone began to show. Searching had not returned but my signal finally had.
I got excited but was told to hold on...still wanted to check on something.
We all waited a few minutes, then carrier rep had me toggle the data roaming off, wait...I still had service. Then, carrier rep had me toggle it back on. Service remained.
No issues since. No more searching. Signal is fine
This was on an iPhone 7 with Verizon.
Since then, I've helped with two iPhone 6 models and a 7 plus. All were refurbished devices.
I made sure I did each step as I was shown and in the order I recalled. I never deviated.
I'm thrilled, to put it mildly and the process is not bad if the connection on the Mac or PC is good in particular.
Please note however, that this issue may not relate specifically to your device or issue. Thus, it may not suit what you need nor resolve the problem.
Also, be sure to backup your data beforehand if you plan on trying it, so you can access it elsewhere. I've since brought over some of the phone's data but did not restore the apps. I redownloaded the apps again instead from the App store. I did bring back Apple music with no issue however, by re-enabling iCloud music library. Basically, I didn't want to chance any possible corrupt data or incompatible data from former backup info to cause any problems and as a precaution, so I was very selective.
****One more thing that I would try before going this process as a possible fix, is to turn off your data roaming and see if this stops the phone from searching.
This may be all you need to do. Again, it depends on your needs and issue.
Basically, the devices I've dealt with on this issue, all needed to have the carrier info checked and corrected as needed by the carrier.
Data roaming was the most prevalent and consistent issue that set the phone into persistent searching/no service mode.
The carrier update installed AFTER updating the device sw, then restoring as new, seemed to be another vital thing/step needed. If you get prompted to update during the process, go ahead and do the update btw.
Finally, completing the steps in a specific order is important. Starting by running the sw update first, by itself on iTunes, then cleaning up the device and not restoring potentially corrupt data from previous backups seemed to only help the device pick up on what the cell service and its settings needed & vice-versa. Essentially, the two seemed to communicate effectively this time and could then work together. Ex: I was never prompted for a carrier update in the past after an update or restore, until this time.
And, can't say it enough, data roaming was definitely causing an issue (on the devices I worked with)
Bottom line though? I couldn't have done this in the first place without the carrier and Apple techs having the patience and knowledge to work with me on this. I tried this several times in the past to no avail, but I now know there were things I wasn't thorough enough on, didn't think to check, and so on.
Again, try turning off data roaming. Ya' never know. This may fix your issue straight away!
If not, there's the entire history of what fixed the 7 and how I've been able to fix three others thus far.
Truly hope it helps those who this could be applicable to in stopping the phone from searching and gaining your cell service back
Best of luck!