Is it possible to resurrect this dead VESC?

I’ve acquired a non-working Stormcore 60D+ from a guy who was attempting a DIY build. From what I’ve gathered, he was just about to configure the VESC using VESC Tool when he accidentally placed it on top of his VX1 receiver. When the aluminum body of the Stormcore made contact with the receiver, it created a short and the VESC has been unresponsive ever since (pressing the power button gives a quick green flash that goes out immediately). Looking at the board, I can’t immediately tell what could be wrong. Any ideas? Pictures below.



Welcome to the forum

I don’t see any visible traces of dead components just by looking at the PCB, have you tried to link it up to a pc and see if the vesc tool might recognise it?

Yep, tried connecting it and VESC tool can’t find it.

On closer inspection, there looks to be a darker area near the 2-pin voltage source. Picture attached

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There are a few things you can check

continuity on a 3.3v pin to ground
continuity on a 5v pin to ground
continuity on that 2 pin V+/GND. That’s after the anti-spark system so it’s useful for checking shorts on the power stage
Hold the power button and feel if precharge resistors (the three big resistors marked “1000”) are getting hot. Recommended to use a CC/CV power supply to watch amps, and limit power into the ESC.

If any of those are short, it helps narrow down what failed.

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sounds like the built in AS is fried, have you tried meassuring on the esc side of the AS? Does voltage come thru? If no, bypass it and see what happens. Report back after that :slight_smile:

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There’s a short on the 3.3v
I haven’t checked the 3 resistors because I don’t have access to that type of power supply.

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Where exactly on the board can I measure that? And how would I be able to bypass the AS?

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The STM32F405VGT6 (biggest chip) is probably shorted out and needs to be replaced :frowning:

Sometimes it can be the canbus chip, or a buck, but it’s usually the STM32.

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What is the circled thing here?
stormcore

I can’t really tell from the pic, but it looks like solder somewhere it shouldn’t be to me. Idk if it’s over the mask or actually connecting traces or what. I could also just be seeing wrong.

That’s pretty unfortunate. The chip itself looks not too expensive but I don’t have the skill set to swap it out.

I was able to confirm that the resistor(s) get hot if I hold the power button down for a bit. Not sure if that confirms/changes the diagnosis

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Turning on when holding the button and the resistors getting hot confirms that the anti-spark IC/system is working, but that there is a short on the other side of the AS. Since there is the 3.3v to ground short, but not a 5v to gnd short, it’s most likely the STM32 chip.

You can see this visually with a shorted chip on a thermal camera

It’s a tricky replacement since there are 100 pins to ensure get fully soldered, but it can be done. Remove the chip, clean & tin the pads, then reflow into place.



and check the 100 pins to make sure they all properly soldered.

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This is very helpful, thanks so much! I might ask a buddy of mine to help me with the soldering since his setup is much nicer.

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Hey, sorry to resurrect this topic, but I do have an update on this VESC. I got the STM32 chip replaced at a local electronics repair shop. They installed an STM32F427VGT6 instead of the STM32F405VGT6 you mentioned as that what was on the board previously and they simply matched the part. Also, the short that I had before is now gone, and they coated the board in some kind of insulating gunk.

However, when I plugged in the VESC to a battery, the switch doesn’t even light up anymore when pressed. I do get a blue and green LED to flash on the board for just a second whenever I press the buttons (picture below), but then nothing.

Any idea what could be wrong now? I’ll attach a few photos of the board if necessary.


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Interesting. The pinout is the same. Maybe it will work :smiley:


After replacing an STM32 chip, it needs the firmware flashed (follow hard method, use firmware below) with an ST-LINK before the green light will come on.

The blue light is just a 5v indicator, but the STM32 turns on the green light through software once it’s fully booted without errors.

Good luck.

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Just double checking…is this how I connect the ST-Link to the SWD port on the Stormcore?
image

And do you have a recommended IDE to upload the firmware?

The knock off ST-LINK V2s are a little easier to use

image

Instructions here

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Last update:

IT WORKS!!! I did have some issues getting the Stormcore to communicate to the computer, but I was able to get it to communicate by disconnecting the main battery and connecting the 3.3v pin to the ST-LINK. Many, many thanks to all your help with this endeavor!

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That looks the same as my boards that I put conformal coating on. It is just an extra layer of protection against any water damage or other unintentional shorts. It burns of easily with a soldering iron although try to avoid breathing in a fumes when it burns off.