iPad Pro 10.5" Same Symptoms as touch disease (kinda)

[LastDeuS]

This iPad arrived with a cracked screen, slightly bent housing and stuck power button,
fixed power button and replaced the screen.
I left the housing like it was maybe applied minimal pressure nothing to disturb the logic board

Then customer returns complaining that touch sometimes stops working.
indeed I test now with the accessibility bubble as soon as I flex the board (like 6 and 6 plus) I lose touch
it does not show any lines of course.
But this behavior is similar to the iPhone 6 specifically and 5S where touch IC fail and a reball is enough so
IFixit said that the touch ics were two broadcomm controllers and I believed them and re-balled those two guys

Of course that did not solve the problem, maybe if I keep on removing one pad will show itself to me as the next m2 what do you guys think?

[Jessa_the_Professa]

There is no reason that flex based no touch would affect the touch ics rather than the CPU, right? I would try to use pressure to narrow down the exact spot that is making poor connection. You can read about the touch system in the iPad Air schematic and guess that it is likely similar for iPad Pro. So a failure point where you have an intermittent open line from flexion could be a connector (unlikely) or at the touch ic master/slave--the cumulus-similar chips, or at the CPU. I would also look at WHERE is the bend in the housing and see if that narrows it down. If you really wanted to know for sure, then you could solder some wires at the connector feet and connect to a multimeter in diode mode. See if any go to OL when you flex the board. Finally, a last clue about where your flexion problem is happening might be to look for hairline cracks in coils this can show you where the fault line is in that device. My guess is that it will be CPU. If I wanted to try and save the device, then i'd think about some kind of janky shim that might help the board not bend, and I would do it for free just to try and help the guy get use out of it, but I can't charge for a repair that I can't warranty. If/when it stops working, i'd ask him to donate it back to me for parts.