Bitcraze Forums

Hi everyone,

I have a few crazyflies for my lab, and one of them (the first one assembled) has been through a lot of crashes and as a result has had some casualties, including the On/Off button that at some point broke off.
A few days ago, the power cable got loose and so I did a little bit of soldering and replaced the power cable on the crazyflie with a JST cable. Now when I plug in a battery, only the M3 Led turns on.
Could it be that I have burnt the processor (or sth else on the board), or could the crazyflie simply need a firmware update. And if so, is there a way to bootload a Crazyflie that doesn't have an On/Off button?
Cheers!

The quick solution is to use something to work as a button. That is something that shorts the pin closest to the chip antenna to GND. A pair of pliers or a wire should work.

Hi Tobias,

so I tried that but I can't connect to the bootloader. Also, the M2 Led is the only one blinking, while normally both M2 and M3 blink when in bootloader.
And when I said in my first post that M3 turns on, I actually meant M2.
This must mean something has been burnt or short-circuited right?

If the blue M3 led doesn't go on it means the STM32 doesn't start. It could be that it does not have a working FW. This is going to be tricky but you can try to get it into the bootloader from a power off state.

1. Disconnect all power
2. Short the button
3. Connect battery power and hold short until M2 starts blinking, then release shorted button.
4. Now hopefully M3 starts blinking as well and you can load new FW.

The above might be a two person job.