How to repair VESC 4.12

I’ve got a VESC 4.12 that’s failed. I’ve replaced it, but would like to learn how to repair it myself. I have hobbyist level electronics skills, reasonable soldering equipment, a reasonable oscilliscope, and can more or less make my way around a schematic. What I’m hoping for is to learn any tips on what items commonly fail on the VESC 4.12 and whether there are any tips on how to diagnose (either functionally or with my scope).

On this particular unit there’s no obvious damage to the board or components. I get a blue light when it’s powered up and a flashing red light when I give it throttle. I can read it’s configuration with the BLDC tool, and it’s producing 5V at the PPM connector to power the receiver. But the motor is no-go. I tried plugging in the other motor, but also no-go.

It would be great if we could start a thread on how to diagnose and repair the most common failures on these things.

Any tips would be greatly appreciated. Thanks.

get the red light again and open up bldc/vesc tool and go to terminal and type “faults” see what is failing. If it’s the common DRV error, hope your SMD soldering skills are up to snuff.

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iT’s tImE tO bREaK oUt tHE hEAt gUn.

Ok in all seriousness, most VESCs fail because the DRV8302 dies due to transients or something else. Most repairs involve replacing the DRV8302, which is more of a pain in the ass than it should be because it needs to be reflowed with hot air.

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I’ll say it again :P.

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pfffff reflow station… too easy, go hard core with manual hot air :smiley:

I joke, my vesc had the same fault, a colleague helped replace the damned DRV, hardest part was to get the chip, they are often out of stock, go order now.

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https://www.arrow.com/en/products/drv8302dca/texas-instruments

142 in stock, free shipping, gogogogo

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I tried replacing mine on my first VESC with manual hot air but I failed. I just bought another VESC and tried to stay happy about it :joy: I still have the old VESC and a spare DRV-chip so I will try it again soon but with more time and patience! I thinks it should be possible even without the right tools.

Just look at SMD soldering videos. Use lots of flux…

https://www.youtube.com/watch?v=c_Qt5CtUlqY

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When I did it, I had to eyeball it, I held the the heat gun to the chip til I saw the majority of the pins/ pads reflow. Held the chip in place using pliers. Held the heat gun directly over the board, perpendicular. I aligned and tacked on all the pins before reflowing.

My issue was not the parts on the opposite side, but the parts right next the drv8302 getting blown away by the hot air. Surface tension should hold the parts on the opposite side on as long as you apply heat for the shortest amount of time as you can.

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Holding the heat gun perfectly perpendicular didnt cause a problem, it wasn’t until I angled it did it start blowing things away. If I could I wouldve used less airflow.

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