Chosen Solution
Apple logo loop, placed it in recovery mode to conect to itunes tried restore and update and then error 4013 comes up. what can it be?
Did you have any issues with the phone before it happened such as the phone being laggy with touch, speaker, microphone not working or speaker icon greyed out on call screen? If yes, the phone has an audio IC fault which causes this issue and would need to be taken to a reputable phone repair shop that does board-level / micro soldering repairs to replace and fix the weak connections under that chip. This can also be caused by a bad U2 Tristar charging chip which then would have to be replaced similarly like above (except without weak connection issue). If this is the case, the symptoms of it is:
- Fake charging (Phone shows charging but no actual power draw from an USB ammeter)
- Phone suddenly stops charging completely
- Apple logo does not appear with battery unplugged and charger plugged in. Worst case scenario is baseband as explained in this linked YouTube video: https://www.youtube.com/watch?v=2T9BVR-o…