[Q] Help with imei null/baseband unknown (I have read so much but still stuck) topic

Hi,

I don't know why this happened. My phone is rooted but just randomly stopped working. It wasn't because of any flash. All I had done was root it about 5 months prior and was still on stock firmware. But now I have no signal. Here is what I have done.

1. Bought new sim board.
2. Flash the parambin file.
3. Tried to the qpst method to use nv reader to manually enter my imei. But the drivers won't work. Always has an ! point next to devices in device manager. Read, could be because I have the international version.
4. Tried flashing 2-3 other modems.
5. Updated to 4.4.4
6. Flash a file EFS_N7100XXND3_KH435987_REV05_user_low_ship to supposedly reset imei. Now I am just in factory mode.
7. Bashed head on desk.

Phone is out of warranty and there are no service centres near me. I really don't want to buy a new phone because I am saving for baby stuff.

Thanks in advance,