How to find rx/tx manually.
Any pinout can be found in 5minutes.
You need to power On phone and measure voltage on test points.
Hardest part here is that battery must be attached, but test points are under battery.
Here I attaching some examples how battery can be attached while you do measurments.
Best result is to use pinfinder cable: one pair of crocodiles you attach to bettery terminals, another pair to battery.
Look for volatges near 2,8 volts, they are tx/rx.
Br.
amn32