So I was in the process of testing my DIY electric longboard when it made a weird sound and stopped working. The day before that I was riding the longboard just fine but after the weird sound, it didn't want to turn its wheels anymore. I suspect maybe because of some vibration something got shorted, but I am not sure. When I got off to check there was a loose wire coming from the battery that powered both ZS-X11H motor drivers. I investigated the problem and after checking everything I found that only one of the motor drivers stopped working.
I started measuring components with my multimeter, I don't know if I am doing this right (this is my first time troubleshooting a more complicated circuit). I checked the MOSFETs and from what I can see I think they are fine (not 100% sure, I just measured if there was continuity between the Source and the Drain and in one direction they were showing 360ohms and on the other nothing (1 on the multimeter) from what i have looked in the internet this seemed fine ).
I tried to measure the output pin that is labeled 5V and it was showing ~3V, so I started folowing the traces coming out of the VCC that powered the driver. I got to a dc to dc converter I checked it (seemed normal compared to the working one) and after that the voltage regulator. I compared the readings from the faulty board to the working one and found out that the voltage regulator's output on the faulty board was showing 1V less than on the working one.
I bought a new one (78L05) and replaced it. After that when I plugged 12V to the driver it in I finally measured 5V on the output so I thought I had fixed it, but long and behold when I connected it to the motor it wasn't working. In fact when I measured again I found out the voltage was dropping slowly from 5v to 4.9, 4.8, 4.7 and so on, when it was working. I touched the board and the regulator was hot.
I think I have burned the new one too, so the issue is somewhere else but I can't find it. From what I can see there are 2 capacitors that are connected to the output of the voltage regulator I really can't tell if they are fine because when i measure their resistance they both show the same value that is also the resistance of the output of the voltage regulator(on the faulty one 1.89Kohms and on the working one - 2.89Kohms).
I don't know what to do, I would really appreciate some advice on what to test next.
I bought a freezing spray and sprayed the whole board, so that I can identify the short. On the pictures you can see a time lapse how it looks when i start it, and how it progresses rapidly in the span of 5 seconds. I can see that first the JY01 starts getting hot, after that the 78L05 regulator and finally the DC to DC converter(XL7005). I don't know what to do with this information. I can't find the JY01 chip (the whole name is JY01c046k00avc3) so that I can replace it and I think I have to replace the regulator too. I don't have a hot air gun so the process is going to be tedious. And the problem is that I can't even figure out how it happened, which is the most interesting part for me, because I can easily get a new one, but I want to know how this one got fried so I can add protection. Any tips would be really appreciated! I am sorry for the late reply, I was not in town.
If your motor drivers are burning, I would look at verifying your motor specifications and get the right-sized driver (or an EV controller). Maybe the motors are pulling too much current?
Well the thing is that the motors are from a friend of mine that bought them from aliexpress a long time ago, the only thing I know for certain is that the motors are 350W and the drivers that I am using are 400W so this should not be the problem I don't think. Besides why did only one of them fail?
You need to know the current draw of the motor, and the controller must be 150% overrated (you can not operate a motor controller at 100% continuously).
Search for a completely enclosed BLDC motor controller. The best ones for miniEVs are US $100 with a set of trucks, motors and controller US$300.
I haven't even run the motor at 100% because I regulate it with a potentiometer and I have only turned it to around 50% of the maxium value, so the motors were never running at full speed, so this isn't the problem.
