Focus Jam2 6.9 not charging & won't turn on - It's dead dead - my dead ebike part 3 

You know what I'm going to say!.....VESC 🙂 Fit a semi-decent BMS. Bin the controller. Replace it with a FlipSky 75100 VESC, filled with Magic-Gel for waterproofing. Update to the latest firmware with the awesome VESCTool - and run HFI commutation. With HFI, you don't even need to connect the hall sensors and the motor will develop more torque than it ever did before. It's all pretty easy and open source - and there are loads of people who can assist. Having converted my bike to a VESC, there's no way I'd go back to a shady OEM controller.

That component looks like a low value resistance used for determine the current flow, the switching noise looks like a maximum current has been reached, thus trying to PWM the input, The hotspots maybe a voltage regulator? Worth looking up what those component functions are, maybe input codes into Google, or even use Google camera 📷

thought you meant anyone want the battery pack. keep it and get it made into a spare for another bike later you know when you do ebike videos ;-)

Definitely ain't as easy as rebuilding a carburettor, that's for sure, makes me wonder how many e-things are or will be dead because of one small component failure, and with a lot of builds like that board being "proprietary", they refuse to release technical documents on the parts used to aid in repair, resutling in a lemon that costs more in replacement parts than the item to be revived is worth, and then ends up in the nearest bin... :(

Seems to me if you have 1.2volts in ground then that chip has tipicaly failed to ground!