Hardware Touch screen not registering

[Ttm3]

I brought 2 motherboards back to life that both have touch screen issues. Both systems work perfectly handheld & dock mode. However neither are will register any touch at all.

I've tried 2 or 3 different housings/screens & 4 different game card readers. No difference. This problem has to be in the board from what I can tell. But I don't know where to look on the board though.
Any ideas?

 

[Ottoclav]

I also began having a problem with my touchscreen after bringing it back to life. I inspected the ribbon cable end, and there is a little bit of damage to it, but nothing that should compromise the connection. Maybe it is really that touchy?

 

[Ttm3]

They are pretty touchy however I tried about 4 different housings so 4 different screens.