Vesc 75300 reparable?


I recently took my board out from winter storage. I used it successfully on Saturday, but on sundey, the easy would not turn on… upon opening the lid and looking at the PCB it shows signs of corrosion/water ingress and something that looks like small explosions next to the large capasitors. the fets look nice but some corrosion.

I just took the PCB out and washed it with alcohol.

there is a bridge between two of the resistors is this supposed to be there?

Any feedback or help on how to repair this would be deeply appreciated!
or maybe i have to get a new one…

Hi, I have a contact in GBG sweden who has my 3 units and 1extra from Vedder himself. He’s spent some 4months on them unsuccesfully but has alot of spare parts by now. We still have not concluded and I’m hoping for atleast 1 back… Unfortunately from both design and competence point of view the 75300 is bad in repairability.

Trampa had the 3 of mine, and there was no chance, but they also admitted to never really had repaired one… only vesc 6. One of them was DOA but as I had removed the lid for inspecttion there was no warranty. also had one with slight water ingress and the last one one motor phase was cut during load as I hit bottom. Apparently this destroys the 75300 directly.

If its only visible damage to 1 component then you should give it a try. Or replace this one your self.
Since I’m done with Trampa, the best recommendation I get from specialists is to go Zesc instead. Also the team triforce A200s seems nice, but cost more than trampa.

Disclosure: my 4:th 75300 has been flawless for 100+ h, so If you manage to integrate it properly, the never Trampa prices are not too bad, even if they can not really give any support on it…

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When you wash it you do mean just pour Isopropyl alcohol on it?

I will take >97% isopropyl alcohol and an old toothbrush and scrub everything down until it is really clean.

I can’t read the part designators but the schematic is available online. Share the circuit part for the blown up part. Wild guess maybe it is the analog or pwm filter parts that somehow got shorted to high voltage


I think it’s probably dead. Sad to see. :sob:

Next time put corrosionX in the enclosure. Fill it till the fluid it just flush with the top of the VESC. This will keep it constantly coated, provide cooling, Corrosion protection, and won’t effect the bluetooth signal.

Moisture is hard on electronics!



Hmm, i have no idea.

but curious if this solder joint is supposed to be there? it could be I have dropped solder ball down inside the esc?

Thanks for the suggestions!, the Zesc looks interesting; nice and compact.

I will do a thorough clean in Isopropanol and cross my fingers, hehe

I also have a local Efoil enthusiast, that is developing a custom ESC. He is kind enough to borrow me one of his prototypes! Rated for 180A and smaller format than the vesc 6. Maybe he will share or make the design available in the future for us all?

Pretty sure that solder ball shouldn’t be there.
But looking at the schematic the voltage divider resistor R50 and the filtering capacitor C73 for the temp sensor are connected in parallel anyways, so it doesn’t look like its the problem.

That Zesc does look interesting and is a nice price too.
This is the most compact option and probably the best form factor I have seen:

Not on mine

Agreed, but it’s 600€+ for us in EU now after brexit. Not an option for most…

Surely with Trampa you suffer the same fate?
They should probably subtract VAT if they are exporting, but I know a lot of businesses are not set up for that yet.

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so strange, hmm now i don’t know what to do, powered it up now and now the blue LED is on.
will try some more testing tonight!

Maybe cleaning fixed it?

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Mine is the first batch before R1 , may be they added this solder after (?)

Cleaning worked of mine rear Sam control unit ( Mercedes ml) , a lot more expensive then a vesc

So why not ? :+1:

You stressed me , so I applied coating on mine , any link to replace the thermal pad ?

Haha, I will do the same if I can figure out if mine actually works.
not looked for it yet, should be able to use any non-conductive thermal tape 0.2-0.4mm?

You might shed less heat if you coated the FETS as well…

3 to 1 wires 80 watt tip.1

Thanks for sharing. I started to solder my 3 vesc motor wires to one 8 AWG that will go through the Gland clamp. Next conformal coat everything. After that take Corrosion X shots daily till cured.

I tied with a 40 Watt soldering iron, it was too light. Switched to 80 Watt and a fat tip. Pre-heating the bullet connectors also helped. I am thinking of sealing the Vesc box with Gorilla Tape, a very strong and waterproof type of duct tape here in the US. Water seems to be the main issue and the VESC’s are not cheap.

Coating the top of the FETs will give much worse thermal performance, would not recommend anyone else doing that, but let us know how it performs after you assemble it back together.
I think the thermal pads are from Conrad, maybe this one:
You can also try to find one on digikey: Make sure it is non-conductive (not carbon) and the same thickness and softness.
I think we have used this one as replacement on the A200S v2 (same fets as 75/300):