First step check all material in the UI plastic bag.

More welding are made using a flux important for a good contact clean, infact a little smd IC like U1 is too small for my eyes.

In the photo the result.

I remember to install the new firmware versions without having the problem of the white screen, at this time you must remove the resistors R30 R31 R32 0 ohm on the back of UI BOARD