Lyen 12 fet sensorless blown EB312

Truusje79

100 mW
Joined
Jan 9, 2010
Messages
41
Location
Limburg, Belgium
So tonight I wanted to make a nice little drive just before it would be dark, so I was a bit in a hurry to connect my battery to the controller, poor visibility and me having a brain-fart led to me having the wrong battery connector connected to my controller.

I connected my 4S battery directly to the controller in reversed polarity instead of taking the right connector with 20S in the right polarity, result was a puff of smoke, some melted wires and a stinky controller, I did it right 100's of times, but now I took the wrong one unfortunately, controller is dead, batteries are still good

Could someone please help me fixing the controller, or put me in the right direction, I can solder some stuff and have a simple multimeter to measure things, but I don't exactly know what all the components are for ( or what they are )
I made some photos.

First bottom side: there was a plastic / paper sheet under the PCB and I put it in mirrorview of the PCB, you can see the burn marks, this small black thing is probably toasted ( what is it ??? )

1yv3hu.png


2chmasm.jpg


Then top side, little red thing smells really bad ( is it a capacitor ??? ), also the shunt wires ( ?!?) look burned, at least not very shiny anymore, the rest looks pretty OK to me, but maybe I killed more components

24gjfd3.jpg


ncffh4.jpg


And some molten wires, outside and inside of the controller, just my luck not enough to let the red touch the black ( big sparks for sure )

2mmh4s2.jpg


All help is very welcome
 
As you can see on the second photo, the solder got so hot it melted from the traces, the controller was in a vertical position when it happened, so the solder dripped down, the little black component ( bottom view ) was directly under the shunt wire which caused the heat and i'm still puzzled what it is, I'm a total noob with these small scale PCB electronics

I found some solder pearls inside the casing like from a solder eruption... :?
 
with no experience there is not much chance to figure it out. you have forward biased the body diode in the mosfets by reversing polarity and also it has reversed polarity on the capacitors so they blew up also along with melting the shunt. not simple.
 
Thanks for the explanation, so this is definitely beyond my knowledge of electronics, but question is: would it be totally unrepairable in the right hands, components would cost next to nothing but if all mosfets died too then it is really not very cost effective to repair it / let it repair
It's a pity to toss 150 EU worth of controller in the bin, would somebody else be interested having a go at this :?: and post his progress on the board, for all ES members to learn, please raise your hands.
 
you can test the mosfets with the diode tester on your voltmeter. if the input caps are shorted they could affect the readings, but you would measure using the diode tester between the red wire of the controller to each of the phase wires, then reverse the probes and measure again. then do the same thing measuring the body diode by measuring between the black wire to the controller and each of the phase wires, then reverse the leads and measure again.

with the red probe on the red controller wire, the black wire on each of the phase wires, they should all measure open circuit. with the black probe on the red wire and red probe on each of the phase wires they should measure about 400mV. the same when you measure using the ground to the controller except the values would be reversed.

that will inform if any of the mosfets burned up. record the numbers and post them up here if you wanna. look at the caps and see if they swelled up and split on the seam at the top.
 
Would love to toy around with this, but I got word from Lyen that I can send the unit back to him, he will try to repair it for me, which I think is excellent service, kudo's for Lyen!!!
I hope he can repair it for me, I can make a nice battery pack, maybe even hook up a BMS and charger to it or change the clutch or head gasket of my car, but this kind of stuff is a bit out of my league unfortunatly, but would love to learn at least some basics, I guess I should have paid more attention at school.
 
Curious as I am, I tested the controller anyway, but first I had to clean up the the molten solder mess ( see photo 1 and 2 ), so I used a solder sucker to get rid of the excess solder that caused a short between source and drain of the " yellow" or 1th phase.

Then I tested like dnmun asked, red probe on red wire ( + ) and the black probe on the phases, they all read open or "1" on multimeter, one observation: first time i did it the numbers increased within 3-4 seconds to 1, when I did it a second time I instandly get 1 on the screen ( caps charging maybe ) waiting some time and it does it the same as the first time.

Black probe on + red wire and on the phases give me readings of 510 - 511 and 514, another multimeter gave 530-530-534 ( very cheapo one, like 6,99 euro )
No continuity between source and drain on all phases, which is in my understanding a good thing, this should give the pulses to the motor but should be closed when the gate is not powered.

So I think, but let the experts be the judge of that, that the mosfets are OK.

When I try continuity on the caps +on+ -on- I get a beep for a fraction of a second then slowly the numbers creep up til I see +/- 1100 mV on the screen, reversing the probes I get the beep again ( little longer ) and I see the numbers go from minus numbers to plus numbers to "open" ...this is + probe on- and -on+

The 2 bigger caps seem to charge up when i set the multimeter on continuity and when switching it back to 2 Volt DC reading, the voltage start to slowly drop to 0, caps look OK to me, I pealed some heatshrink away but I don't see rupture / bulging on them, I don't even know if this is a proper way to test them, or if I even can test them soldered on the pcb like this, I'm just reporting what my findings are.

Other things to test???
 
Just let Lyen do his stuff. He knows the circuit and what else might have been affected- some blow but still look fine. He even road tests the controllers after testing! There's a utube of my controller out there.
 
Update: Lyen did his stuff, he replaced the cables and the shunt, so for 45 dollar including 2 X shipping and repair it's working again.

As far as I know nothing else was broken, no caps or mosfets, so although it smoked like hell and looked horrible, I got away lucky.
 
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