Focbox Unity Will Not Turn On

I was riding my board and it just stopped with a full battery. It has very little use, only a few miles on my board. After a long walk home and checking the battery, discovered the Focbox Unity will not turn on. I followed the instructions on how fix the bootloader for my unity with a ST-Link V2 programmer, however, the programmer would not connect and it would lose connection to my computer. The programmer would lose connection to my computer, unless, I disconnected the 3.3V connection to the Focbox and it would connect to the computer, but not the Focbox. Could not find any burnt circuits, however, I did not disable heat sinks from the board to look under them. Any recommendations on how to fix it or someone to repair it in the USA? Thank you!

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@jaykup can most likely repair it for you, but it’s possible that you could also just use a loop key.

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If the STLINK is not working when the 3.3v is connected, then it’s very likely that the STM32 processor is shorted out. To verify this, check the 3.3v to gnd with an ohm meter while the Focbox is unpowered. I’m guessing it’s shorted, or at least around 1 ohm. Should be many mohms.


Thank you for the advice. I measured the resistance to be 2.9ohms, not near the mOhms it should be. Do you have any idea the cause of the short or can it be repaired? I look at the board to see if the pins were shorted, only can see some of the double sided tape holding the bluetooth board to the the processor touching the pins, I tried to clean it no change in the resistance (it appears the processor is partially covered in a conformal coating). Thanks again.

Should be many megaohms, which is more than many milliohms.