Hey guys, so I was probing the Betaflight F3 with a multimeter checking for loose solder joints when I got smoke, I must have shorted something by accident. It looks like I have blown some sort of resistor (circled in red in my image). Does anyone know what that component is, whether it is needed at all for a simple quad, and whether it can be fixed? Thanks in advance!

Just guessing but it looks like it ties the second pin above the resistor to ground, to prevent a floating signal on the pin and would be from 1k to 5k ohms. I'd measure the bottom of the resistor to ground, if you have continuity then that should be the case. Before suggesting to replace it the real question is how did it smoke a resistor? If it is a pull-down resistor there shouldn't have been any voltage on the resistor. Any guess as to what caused it to smoke?


Also, you should never leave an input pin floating, so if was just shorted by your probing I'd suggest replacing it. Possibly with a through hole resistor, much easier to solder than smd components.

The resistor in question is part of the voltage divider for the input to the A/D on the MCU that is used to measure your flight battery voltage. The resistor to the left of the smoked one has full battery voltage at the lower end when the board is powered. If you accidentally shorted the two lower ends of the resistors with your probe, you placed a direct short across the battery.

I don't know what the exact values are for these two resistors.It looks as if you've smoked the end of the resistor where it connects to ground. Most likely, your voltage monitor won't work any more.