Replaced USB-C side board, touch screen goes nuts

[Zebulon Walton]

Back when I replaced my cracked screen I managed to damage the vibration motor attached to the USB-C board. Not a really vital function, but I went ahead and ordered another board to replace it.

After installation there is still no vibration, but the worst part is that the touch screen has become erratic. It acts as though an "invisible finger" is giving it random input and doesn't react predictably to real touch. I reseated cable connections on the USB board and main board but still the same result. Also tried booting off an SD card rather then eMMC with no change. (It didn't seem like a software problem but I wanted to make sure.) Putting the old USB board back in also didn't change anything.

So... what is the most likely thing I messed up while in there?

[Zebulon Walton]

Update:  It appears the problem was caused by a new charger that I was using. I've been using a generic 2A USB charger from eBay that worked perfectly. So I ordered another one as a spare, and that came in the same time as my USB side board. So I didn't give a thought to powering the phone up with the new charger after installing the new side board. (I normally have the phone plugged into the mains when using it at home.)

Turns out that if I use the old charger or just run off the battery that the phone works fine. So the new charger is either off voltage or sending some kind of disruptive signal or spikes into the phone and making it go crazy.

As far as the buzzer problem I'm not sure why that didn't work when the new USB board was installed. Of course the wiring is fragile but as far as I can see nothing was damaged. It maybe be related to the same problem, so when I get a chance I'll try reinstalling the new board.

[israel]

Update:  It appears the problem was caused by a new charger that I was using. I've been using a generic 2A USB charger from eBay that worked perfectly. So I ordered another one as a spare, and that came in the same time as my USB side board. So I didn't give a thought to powering the phone up with the new charger after installing the new side board. (I normally have the phone plugged into the mains when using it at home.)

Turns out that if I use the old charger or just run off the battery that the phone works fine. So the new charger is either off voltage or sending some kind of disruptive signal or spikes into the phone and making it go crazy.

As far as the buzzer problem I'm not sure why that didn't work when the new USB board was installed. Of course the wiring is fragile but as far as I can see nothing was damaged. It maybe be related to the same problem, so when I get a chance I'll try reinstalling the new board.

Figure anything out on this one?