Ipad 4 stuck in headphone mode
So iv got an ipad 4 thats had water damage and its stuck in headphone mode. Its not the flex as if I unplug the flex and restart the ipad it still thinks the heaphones are plugged in even though there isnt even a headphone flex plugged in.
I do microsoldering repairs and have always wondered how the headphone detect actually works, as iv seen this issue on an ipod before too.
On the heaphone line coming out of the audio ic there is the CODEC_HP_DET line, it then gets to a resistor which I presume is to prevent over current, and then a ferrite, which I presume is to prevent emi / smooth the signal.
Then from there it goes to the flex connector, but from there its a mystery......
Is there a line that connects to here to push it high or is it pulled to ground when the headphones are plugged in ?.
Im just wondering as they dont care about the heaphone socket, as they just use the speaker on it, so wasnt sure if I pulled that line down or if I can solder it to another line to pull it high to turn off the heaphones.
The only other option is changing the audio ic and that is caked in underfill and has the touch ic on the other side of the board so is a bit of a risky one.
Id just really like to know how the circuit itself works really.
Another odd thing is, that when playing system sounds it plays through the speakers just fine, and if I click on the volume buttons when not on youtube it says 'volume', yet when I go into youtube on safari it says 'headphones'., also if I record with the camera it says headphones too.