How to confirm it is Baseband problem:
- If you haven’t restore yet, go to phone menu. Press *#06#. It will show your iPhone IMEI.
Nothing appear after you press *#06#, then it’s confirm you having Baseband problem.
- Try dial 112. Baseband problem will just show you call failed (it’s emergency call number which must be able to call out in most country, even for a locked iPhone)
- Error 1 or -1 in iTunes restored failed. (Only iPhone 6, 6P and older models)
- Error 4013 (iPhone 6S, 6SP, 7, 7P, 8, 8P) After fail restored, you still see iTunes logo in your iPhone.
Please note: THIS WILL NOT WORK ON NETWORK BLOCKED PHONES.
Why did the problem happen?
A: Usually is because you dropped it too hard.
WHY? My other iPhone doesn’t have this kind of issue even if I drop it thousand of times
A: I can tell you It is the Design Flaw.
Because the baseband IC is sitting middle of the logic board. So when the iPhone7 fell hard on the floor, the long logicboard will get slightly bend on middle and return to a position but…
By so many black glues bound between the PCB and this IC, the joint of this IC will still get cracked or lost contact to the board.
So how to fix it?
A: Most of the cases, it just needs reball the Baseband CPU with a better solder paste which is more durable than Apple. Sometimes even need to repair broken tracks below at this IC.
We must take it out to check.
To do this job, the technician himself MUST BE very skillful and experience. Master of heat control.
Why? Because CPU is SITTING next to it!! If you put too much heat, A10 CPU beside will be shorted or died. CPU’s hundreds of solder balls will be messed up/disturbed by underfilled black glue.