1697 U3 and U1 HOT!!!

[renan.horste]

Hello guys, i have a 1697 controller, he wont turn on with batteries, when i put the USB, he turn on and the led blink but anything work, and U1 and U3 was incredibly HOT!!
i dont find and shorts in capacitor, TP26 is shorted, he is a GND tp?

[RDC]

Test the top board alone, do not connect the bottom board to it.

Plug up the USB cable and see if U1/U3 get hot then. If they do get hot, suspect they are bad or something on the 3.3v rail of that board could be shorted. If they do not get hot, check the voltage at U1 pin 5 (should be 3v) and at U3 pin 2 (should be 3.3v) If those are all good then suspect a 3.3v short on the bottom board somewhere.

[renan.horste]

Dear lord, I forgot to say, U3 in Button Board are hot and U1 in MCU board, I already change the top board. The problem is in MCU board, but where?

[RDC]

If U1 on the MCU board is getting hot then it's probably toast and causing U3 to get hot since it's the one that makes the 3.3v for everything.