No touch screen

Hello my friends, I have a LITE for repair that the touch screen is not working, I already changed the connector, I tested 2 other screens, finally I changed the IC BGA too, without success, I noticed that a capacitor next to the IC which should reach 10v, only 2.8v is arriving, does anyone know where I should go now?

this capacitor
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Can’t say I’ve delved too deeply into the touch screen circuitry either for regular Switch Revs but also Lites… If it were me and I was looking to identify faults and map out the circuit then I’d start by getting making out a pinout continuity map… you’ve seen these before in the images I post (colour to colour etc) afair the Switch Lites use the same digitizer connector as a regular revision switch right?

Regardless I’d buzz out where the connector pins are all going on a known good and mark them in a photo using a known good board, put emphasis on identifying which pins are key PSU rails etc etc, then cross compare with your bad board and see if anythings not showing up where it’s supposed to and if so why not.

For example I don’t have a clue where or what that 10V rail /signal your measuring on your good PCB and what it’s for… or if it’s provided elsewhere on the board or generated intenally by the touch IC :thinking:

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In reverse conduction (red GND and black lead on the terminal) all values ​​are OK compared to a good board, the only thing I found different was those 10v that feed the IC, which on the bad board is only reaching 2.8v, I tried with the multimetro see where the trail is coming from but not found (maybe apu)?