Here’s a link to the esc which they have used:
Can you tell us how much voltage the battery is giving out. I saw on the specifications of the battery that Max voltage is over 60 volts. Which would result in overcharging the battery.
Maximum charge should be 58,8V in your setup. Absolute Lowest discharge voltage is 35 volt. Below that the battery will be damaged.
Can you contact the seller? From your description, it seems very likely that the issue is with the battery rather than the ESC. If you have a way to test the battery or borrow a battery from another EFOIL to test, that could help.
I think I can handle replacing the esc, I found the same one on the internet, there are 3 wires coming in and 3 wires coming out, I can connect that. But how can I tell that it’s not the engine? I haven’t measured anything with a multimeter, except for the battery itself. What is a remote transmitter? And what is a bluetooth unit?
As far as I understood from chatgpt, the speed controller is what is in the board, correct? but I don’t have anything there, as I wrote above, I unscrewed everything that could be unscrewed in the board, and I didn’t find any elements there.
What was the actual battery voltage?
The board has a receiver to receive signal from the transmitter and send it to the ESC.
If the motor is turning by hand it may be alright.
If you replace the ESC, you need to ensure all connections are waterproof.
Don’t go to ChatGPT, its just going to confuse you more. It doesnt know which board you have and if it cant find that, then it will just approximate based on whats more popular in its training.
There is a third wire near the back of the board. That most likely runs to the receiver.
You have joined the forum and haven’t spent any time reading to gain an understanding of the terminology. Many of the terms in the answers you have received have the same meaning.
For example ESC - VESC - speed controller are all the same thing.
Your initial post included a video that is several months old so apparently things aren’t that urgent for you.
Please do some reading here before you start taking anything else apart and/or spending money on parts that you think you can replace yourself.
My advice is to face the fact that you bought a cheap knockoff product that will likely never be any good even if you manage to fix it. Sell it for what you can and buy a reputable brand board and get out on the water and enjoy yourself.
Bit harsh I know but if you don’t currently have the knowledge to make a “safe” repair and seem to now be in a rush to get it working maybe that’s your best course of action. 
are you sure? are you sure? that is, in the board, there is some kind of receiver that I don’t see? or maybe it is that there is no receiver?
That is the 3rd wire from the ESC to board and will be linked to the receiver. Exactly where the receiver is in the board I don’t know, but you will need to try figure that out.
I see 3 options for failure:
If you have a spare remote and receiver, then you can just unplug and plug the new one in and eliminate that entity.
Assuming the motor still turns by hand when off, then you can assume that its not the culprit and swap out the ESC.
Finally if its not those, then you’d need to swap out the motor…
I don’t think its a terrible efoil, I just think that buying from China directly should be for those that are savvy with electronics. For the major brands, the extra money you pay is for the support model.
PLEASE Tell me, how do I find out which one?
already corrected. please read more.
If you’ve bought a spare remote, it should have come with a spare receiver too.
okay, thanks. to get it out of there, you need to break the structure - that is, break it, destroy it, since it is imprinted inside. I can do it. What should I do? Is this normal?
How do you connect the mast to the board?
Is there a big plug? The battery and the signal wires pass through that so this needs to be in good condition with no corrosion etc.
there was water there - is that normal?
