[Galaxy S III Q&A, Help & Troubleshooting] :
Hi guys,

First of all, I'd like to say that I HAVE searched all the different threads -- both on XDA and on the webs -- and I cannot solve my issues. In fact, they seem to keep getting worse! If I could just take a moment to explain my issues below, I'd appreciate if anyone could help at all.

I bought the International verison of the S 3 from eBay (regretting that now). All was fine when I unboxed it (it connected to networks, etc.). It came with 4.1.1 out of the box. However, when I did OVER-THE-AIR updates from Samsung (to 4.1.2), this seemed to have either corrupted or destroyed my /efs/ folder. The phone would pickup my network (LIFE Mobile, in the UK), but it was say "Not Registered on Network". This is where my problems began.

1) I thought "Hey, no worries! I'll just factory restore." - This did not work.

2) I began researching the issue, and at first I did not understand the issue much, so I went through various fixes.

3) I rooted the phone with CF Auto Root, and installed Busy Box. I then tried the ARIZA Patch, which did not work.

4) I realised the issue was to do with my IMEI being a generic number (ending in 0000), so I then flashed a new ROM (4.3) in a hope that this would correct the issues.

5) The new ROM did not fix anything. I still had the wrong IMEI, so I rooted the phone again, copied my /efs/ folder to my SD card, deleted the /efs/ folder, and rebooted, in the hope that this would fix the /efs/ folder. It didn't work.

6) I then ran Triangle Away to remove the flash counter, which worked. I did this because I was going to send the phone back (without them knowing I tampered with it), however, since deleting the /efs/ folder, my device seems to be stuck in Factory Mode (even AFTER restoring my /efs/ folder).

7) I then trying all sorts of common fixes, including changing the word in the factorymode text file to "ON", but this hasn't worked. I've also ran the following commands with ADB Shell, which gave NO errors, but still didn't work:

su

rm /efs/FactoryApp/keystr

rm /efs/FactoryApp/factorymode

echo -n ON >> /efs/FactoryApp/keystr

echo -n ON >> /efs/FactoryApp/factorymode

chown 1000.1000 /efs/FactoryApp/keystr

chown 1000.1000 /efs/FactoryApp/factorymode

chmod 0744 /efs/FactoryApp/keystr

chmod 0744 /efs/FactoryApp/factorymode

reboot

8) My device was still in Factory Mode, so I did a factory reset from the stock recovery, and also flashed back down to 4.1.2.

9) My device is still stuck in Factory Mode, so I tried some of the fixes that are in the program "EFS Professional", which has /efs/ permission fixes and Factory Mode > User Mode tweaks. It ran successfully but my device is still in Factory Mode.

And this is where I'm up to. Stuck, confused and utterly stressed. I've spent the last 12 hours trying to fix this issue. I've tried flashing new modem.bin files, I've tried all sorts of ROMs, nothing. So to recap:

My device which I've JUST BOUGHT and updated OFFICIALLY is now f***ed. It is not reading my IMEI number, and is stuck in Factory Mode. I have no idea how to get this working again. I will also details the "ap cp csc" versions that were on ORIGINALLY (when the last official update was installed), and the "ap cp csc" versions that are on there NOW:

Previously:

PDA: I9300XXEMG5

CSC: I9300ODDEMG1

MODEM: I9300DDEMG2

Now:

PDA: I9300XXEMF1

CSC: I9300VFGEMF1

MODEM: I9300DDEMG2

Thank you for taking the time to (hopefully) read the entire post.