VESC6 broke while cruising

Ello everybody.

I ride a full Trampa Urban Carver monster-box build, which i got all the way back in June 2018, just with an added wand 2019.
2VESC6, 263xx 154kv motor, 12s6p li-ion Sanyo 20700B cells, no BMS.
Nearly driven 14000 km on it all together, and worn down 4 sets of tyres - no problems at all.

Yesterday while i was out riding, my board kind of freezes during a little acceleration, and then stops responding all together, bringing me to a slow stop. Dis-reconnecting my anti-spark to the VESC’s does nothing to bring back the board to life, and the WAND remains unable to see the BLE module. I’d barely made it 300 meters from my home when this happened, so luckily, not a long walk home.
Coming home, i see my main VESC has no lights in it. Nor can i connect it to the computer via USB.

Taking the VESC apart, it looks like the DRV’s could be fried.

Checked all phase wires in the motors - seems to be working fine.
I did just splice all of the wires from the hall sensors, 3 weeks ago, but these cables are all still well insulated from one another, as far as i can measure.

Could this be related to, maybe, the anti-spark switch not being plugged all the way in, resulting in some under/over voltage? Or some other issue related to the anti-spark switches? I didn’t get to check for this exact issue out on the road, since i panicked ever so slightly - but it’s one of many things which could be the killer.
I’ve never had break/use currents set above the battery-limit, nor charged the cell’s above 4.10V, to have a buffer for breaking.
Never been a fan of BMS, since they’ve been known to shut off during different charge/drain situations and kill VESC’s.

Anyone who knows if it’s even possible to repair?

@Trampa Frank, do you have any ideas, where i could’ve gone wrong?


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Check if 3.3V (labelled VCC) is a short to ground.

What would i connect to where to check if it’s shorted to ground? :slight_smile:

It should be marked on the pcb and on the esc casing.

Measure resistance between vcc and gnd.

I tag @seaborder maybe he can help you out with a repair.


that mosfet heatsink badding is due for a change.

As gamer said, see if you have the 3.3V rail.
If possible, connect your vesc to a labsupply to see what kind of current it draws. I dont recommend connecting faulty HW to a live battery.

If you have a short between ground and vcc its most likely either the regulator or the MCUs thats gone.
If you have no short, but not 3.3V when you power it on. Its most likly the DRV that gave up.

Either way you prob have some repairing to do. Unless @Trampa can help you, if your warranty is still active.

Hmm, i get 000.6 ohm resistance through vcc and gnd - so i guess that looks fine? :-S

thats a short circuit.

Something most likely blew the MCU, stray wire or piece of debris


Damn it :frowning:

Could the short could come from either the BLE module grounding somewhere, or the Hall sensor cables?

Typically hall sensor cables coming into contact with phase wires.
It blows up MCU and MCU becomes a short.

@seaborder should be able to fix it. Don’t plug that motor into another VESC!


Yeah it’s ooold! I’ve ridden em quite a lot now! Warranty is deffi not there anymore, since they’ve just passed the 2 year mark :wink:

But as gamer said, it looks like the 3.3 is shorted somehow - but i gotta figure out how! :open_mouth:

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Could be more than one thing wrong, first step would be to lift the MCU to see that the short dissapears. If thats all there was, then maybe MCU swap is all that is needed. If the short caused a big current draw then It can blow regulator and DRV as well. So time will tell.

After that I recommend checking the insides of your enclosure and see that no wires are damaged or shorting on anything else.

I definitely won’t! I won’t dare frying my last one, till i find out where it went wrong, and where it shorted. :slight_smile:

It very well could be related to the hall sensor wires! I’ve had some unlucky incidents, where branches has ripped the hall sensor cables in half, twice! So I’ve had to splice those little 24-28 awg wires twice! But going through em, they still look very well protected all of em

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It is usually the PCB inside the motor.Simply use HFI