Last night, I attempted (and eventually succeeded) at reverting my SGH-I747 to the stock 4.1.1 ROM, with the intention of subsequently installing the 4.3 and 4.4 OTAs. However, I was unable to do this because the phone behaved as though no SIM had been inserted, despite the fact that one had. At various points throughout today, I've performed factory resets, re-flashed the 4.1.1 ROM, and gone back to CM11 (under which my cellular connection had been fully functional up until last night), all with no results. My next thought was that the SIM card itself had somehow broken*, so I looked through AT&T's process for ordering a new SIM. However, I am unable to view the phones IMEI (which is required for such ordering) through software. Obviously, I could just pull out the battery and look at the IMEI there, but I worry that the lack of ability to view it in software is indicitave of some sort of problem with the phone.
My main concern is, is this a problem that I can easily solve? Or have I irrevocably screwed up my phone's SIM slot (or some other piece of related hardware) which I need to replace in order to recieve mobile communication?
Any help much appreciated.
*Before anyone asks, I am unable to test the SIM in a different device, as neither I nor anyone I know has a device on AT&T with a micro-SIM slot whose phone I can borrow for that purpose.