Ipad 5 A1822 data connection problem

[Kvant]

Hi

I take iPad 5 no power, no charge (0.00A from lighting)
Battery 0V, i charged the battery - the iPad started up normally, but still not charging
i have checked the data connections between the connector and coil in front the tristar. all OK
I replaced the tristar, the iPad started charging, but it is not detected on the PC
I connected the lightning headphones - the headphones are detected and work normally
I replaced the tristar again, but nothing has changed.
I remove ESD protection from all data lines, but nothing has changed.

To start charging, 2.8V is formed on the DATE contacts, when the working iPad is connected, this voltage drops to 2.5V. In my case, the voltage drops to 1.2V at D + and 0.2V at D-.
When i connected iPad to PC, i have 0.00V on D+ and 0.06V on D-, from time to time rise voltage. see video https://y o u t u.be/sCjlXgjRsAs

In diod mode testing
E75_DPAIR1_CONN_P - 740
E75_DPAIR1_CONN_N - 740
E75_DPAIR2_CONN_P - 745
E75_DPAIR2_CONN_N - 745
other contacts can’t say with certainty, because I don’t have a circuit

Please, help with schematic or other information

[Kvant]

Ppout_e75_acc_id1 - 400
ppout_e75_acc_id2 - 405

[timvandenboo]

The ipad 2017 has the same crappy dockflex as the ipad air.
Commonly, I fix the ipad air/5 with no charge problems by the following three checks.
1. change dock flex or tristar. (depends on what my tristar tester tells me)
2. change tristar or dock flex depending on step 1.
3. check the E75 lines you already mentioned.

[Kvant]

Yes, I using air schematic, I change tristar (now charge work fine), I check data lines (I can find double coil on data lines) - all ok. But ipad won't connect to PC. I want check communication between tristar and cpu, but I can't find testpoints.

[Kvant]

I remove the TRISTAR and check lines by Diode Mode. I see abnormal resistance on B3 and A3(?). This is lines to CPU
iPad Air Diode mode U6000.JPG