Repairing controller 2v problem

Joost

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Joined
Mar 31, 2014
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54
Hello all,

I want to ask you if there a people that can help me too solve the 2v problem on my escooter controller.
Yesterday I tried too repair it but could not find the problem. All caps and mosfets seems oke.
The problem is that I get only 2 volts where it should be 5 volts.

I have a 12fet controller from Nanjing Yuanlang.

What are the steps too make it work again?

Joost
 
The first thing I'd check is the battery in my multimeter.

Then find the 5V voltage regulator on the board, probably a tiny sot23 SMD part (or maybe a TO220 like a MOSFET) . It will be connected in line with/close to the main power in.
 
I've changed the battery but that wasn't it. A stupid question: the ignition key/switch will this disconnected or connecting the circuit? I'm struggling with a stupid alarm, if I connect it to the battery directly I can use the seat-unlock and hearing the alarm sound.
 
If I disconnect the controller I messure 48,8V, but when I connect the controller it drops too 18V! I claims slowly from 11V too 18V.

Is this a mosfet failure?
 
I'm not really sure what problem you're troubleshooting now, but:

If you measure either 48 or 18v at the 5v line, then the low-voltage-power-supply inside the controller is fried, and it has destroyed all of the low voltage parts inside it.


If you are measuring something other than the 5v line now, and getting 48v in one case and 18v in the other, you will have to give the full details of this new and different problem that you are troubleshooting. Or if it is part of the same problem, you will still have to tell us where you are measuring to get those voltages.


You had a previous problem with your battery, which you didn't help us help you by providing the info we asked for, and didn't report the results of the tests we asked you to do.
https://endless-sphere.com/forums/viewtopic.php?f=14&t=87409
If you don't provide all the info, all of the exact steps you are doing, along with the exact results for each step, one at a time, it is going to be very hard for us to help you with this new problem, too.


FWIW, if you did not fix the battery problem, then it is very likely that there is nothing wrong with the rest of your bike, and the battery is still broken, causing all of your other problems.
 
Sorry for the bad information.

Battery is solved but I'm waiting too the dongle so I can reprogram the bms. The fault was on the multimeter side. I was reading different values than my lipo charger and alc 8500 expert station.

Too solve it I bought a better multimeter.

About the controller problem and measurements I hope make it clear.

I have opened the controller and measured ass followed:

Battery directly 48V
Battery connect and switched on the black probe on the negative side off the controller outside the controller. The red probe inside the controller on the positive input. Now I measured voltage slowly claiming too about 20V.
When I hold the negative probe on the negative input and the positive probe one by one on the mosfets I measured the first two mosfets 0V the next two 20V the next two ones 0V so on....
Das this means the mosfets are gone?
 
Joost said:
Battery directly 48V
Is that with the controller connected?

Or just battery and nothing else connected to it?



Battery connect and switched on the black probe on the negative side off the controller outside the controller. The red probe inside the controller on the positive input. Now I measured voltage slowly claiming too about 20V.

If the voltage inside the controller, where the battery input wire (red?) is soldered on the board, is not the same as the battery voltage, then there is a problem with the connections between the battery and the controller (could be anywhere, in wires themselves or solder joints or connectors or crimps).

If the voltage inside the controller is actually the same as the battery, and the battery is no longer outputting the correct voltage when the controller is connected, then the problem is still in the battery, and you would need to fix that first.




If I understand correctly where you are measuring, the MOSFETs (FETs) should have alternating voltages on them, because they work in pairs (or rather 3 sets of two pairs in a 12FET controller). So there is probably nothing wrong with them. But if you think there might be, you can go to http://www.ebikes.ca/learn/troubleshooting.html and do the FET testing per the documents there.
 
I found the problem......
It's the Smart BMS! When I connect a load as a controller it cuts off. I reproduce it by connecting a lamp and the BMS disconnect the output power.

A strange thing is that the BMS's led not lights up.
Is there a way too force the BMS in balance mode? C7 won't help.
 
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