Hello. i got in a modded switch lite, that has no buttons working except for home, volume and power. Joysticks dont work either. I replaced the STM with one from a donor board and the exact same issue. There is no voltage on any button pads, so I take it the stm chip is not booting up, but there is 1.8v on it’s vdd pins.
What could cause it to not send voltage to it’s gpio pins? I would guess some sort of reset signal, but it’s reset pin only goes to pin 36, so it reset’s itself? What else could it be?
Sorry, forgot to mention. I have been over the board at least 3 times, and have found no missing components or shorts. The client stated that it was working for a few days after someone installed the modchip. All of a sudden it stopped working.
After testing more, Pin 20, which is “Device power-on reset input”, is low. but even if I inject a voltage (2.9v) there is still no voltage on buttons. So I am guessing that the cpu sends an “activate” signal over I2c or something that boots the processor. But now I’m just guessing. I wish there was more documentation on the coding of this microprocessor