Chosen Solution
I was replacing broken digitizer ( i guess thats my 4th time ) but this time i messed up FPC LCD connector on Logic board so thats need replacing , but i have actually , carefully but completely remove ( stripped down ) LCD connector from PCB , and all soldering pins looks ok, Now obviously iPad LCD screen in not connected so i am only relaying whats showing in iTunes . So before i completely remove FCP connector from logic board iTunes was still able to detect iPad as normal , then for a while : with FPC connector already removed iTunes was not detecting my iPad , only if i put it recovery mode, then i try detaching Logic board form battery , all connector ,putting it all back together etc. and now iTunes not detecting it at all , not even in recovery mode! Also tried reiboot mac app , to get out of look ,but reiboot also not detecting it. I don’t think battery getting charge when connected to apple charger . Tried few different cables , all good tested on my other apple devices. Ipad dock connector i think its fine , The only sign i get from iPad is when i connect to charger there is some very weak not very noticeable ,but high pitch type of sound /noise coming from logic board , from around A6X chip or even down below where dock connector on logic board is ,hard to say as its really really weak and its all over , i guess that is proof that its getting power to logic board from charger.Its not happening when its only connected to battery ( which are probably drained and not being charged , even if left charging all night )
Did you isolate the battery from the logic board (or better yet, remove the logic board) before attempting to remove the FPC connector? If you didn’t, then you probably shorted some adjacent pins and caused logic board damage. This will require some board level troubleshooting.
