Chaka's VESC repair log

Now that I am servicing/repairing VESC’s I thought I might keep a log of the various failures and solutions. I hope it may become useful for anyone attempting to repair a VESC on their own.

I will do my best to keep this thread updated and document how I bring these beautiful pieces of hardware back to life.


The latest VESC I have repaired was a pretty common short circuit failure caused by an exposed wire.

If you are lucky and only shorted the ppm header/ 3 pin servo connector, then sometimes you can replace the tvs diode and all will be well. More often then not a short will cause the stm chip to fail and possibly the drv8302 mosfet driver.

This VESC was reported to have been shorted and the led’s were not lighting up anymore. The vesc was indeed unresponsive upon arrival. When powered the voltage regulator would heat up signaling a short circuit had developed somewhere.

I was doubtful that the vreg had failed but to be sure, I used canned air to frost the board and carefully watched the stm processor as I powered the board once again. Sure enough the stm chip quickly thawed the frost signaling it had developed a short and needed to be replaced. Sure, using canned air seems crude but, as I recently found out from other community members, is a very sound way of detecting hot spots and shorts.

After replacing the stm chip with a hot air station the vesc once again came back to life when powered. Of course it being a fresh chip it was in need of firmware and the bootloader. After it was flashed I attempted to run motor detection with the bldc-tool and it failed. I checked the terminal for faults and as I suspected it was the drv8302.

Another round on the hot air station with a fresh driver and our once dead VESC was back in business!


Hi @chaka, I’m looking for a tip: When you remove the MCU or the DRV, there’s still little mounds of solder on the pcb pads, which -in my experience- makes it diffcult to keep the replacement chip alingned with te pads. How do you cope with that ? Thanks.

From my experience with surface mount soldering, you can use SOLDER WICK to absorb residual solder and re-apply new solder afterwards. Solder wick also came in many sizes. Cheers

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I actually place the chip while the solder is still in its molten state. I do not recommend this to anyone who hasn’t placed at least a few hundred of these chips though. Don’t worry I preheat the chip before doing this. :wink:

Another method I use is by using “no-clean” flux and letting it dry till it gets tacky. This helps keep the chip in place while I apply hot air. The chip always ends up moving a bit when the solder begins to flow so some final alignment is necessary at that point.

You do need to be sure to apply enough heat before aligning since you can lift some pads if the solder re-solidifies while in the process.


After having repaired several VESC’s from other manufactures we regret to announce we will only be providing a repair service for existing customers on Ollin made VESC’s.

We are seeing too many quality control issues and cannot bring them up to our standards without completely rebuilding with quality components on fresh pcb’s. We may offer some sort of salvage service in the future to those stuck with bunk VESC’s, giving a credit for the few usable components that match Vedder’s BOM. It might add up to a $15 to $20 savings.


I have a vesc that flashed no problem but when I hooked up a 12v battery I noticed some smoke… I believe the LEDs or the blue one atleast still comes on. Would you recommend replacing the small 32bit processor, And do you think anything else is fried?

Check the tvs diode, that is what is probably heating up. If it is you will want to check the stm chip it could have some bridged legs or faulty like you are thinking.

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So i put a different stm chip on and I can flash the vesc successfully and have a blue led but I removed the motor driver. but when I hook the battery up I get no lights is this because I removed the motor driver? I have no clue how I’m going to get another one on because it’s hard to tell if the pad is soldered underneath. Is there a diode that could have went bad and that’s why I have no power lights when a battery is hooked up? Basically does the motor driver have to be on for the vesc to get power with a battery?

The drv chip has a buck converter that supplies the 5v rail. When the programmer is attatched the 5v is supplied by the usb.

Upload some photos when you get a chance.

here is a picture if I replace the drv is there anything else that could be bad

It is hard to be sure but it looks like there is a lot of residual solder paste on the pcb. You may want to give it a good Iso alcohol bath after you replace the drv chip. That could have been the initial cause of the 5v short.

I use a 10x loupe to check the pins. Do you have one you can use?

No not really sure what that is and should I just take like a tooth brush and alcohol and scrub the pins on the stm n drv?

Yeah that would work but I took another look and it looks like the solder paste under the mosfets did not flow properly. You may want to add some liquid flux and use the hot air machine to get those areas to flow. It can be a difficult area due to the extra mass of the mosfets soaking up most of the heat.

How hot do I dare turn my reflow station up I don’t want to damage the component or the pcb board

I’m hoping tonight to resolver the drv on I’ll take pictures of that and the mosfets before I try power it with a battery… I don’t own a power supply but am starting to consider buying one

Probably a dumb question but the mosfets not being soldered by the back would that cause it not to connect to the PC? Also if I bought a power supply would that shut down if there was a short and prevent stuff being fried?

No but it will cause hardware faults. The residual solder paste could cause the issues you were having.

Resoldered the drv on and this is how it turned out also fixed the mosfets but I don’t know if I dare plug it into a battery

You could try using a pair of 9v alkaline batteries in series. I haven’t tried it but I don’t think they have enough amperage to fry the vesc. I single 9v might work but it is very close the the low voltage threshold and my throw fault codes