Brainpower controller with S866 display DOA

[bneccs]

Hi, my ebike stopped working a couple of days ago. The display is a S866 and the controller is a Brainpower.

I wasn't doing anything weird, the PAS was in 3 out of 9, I was actually going down the hill and suddenly the controller switched off.

I'm trying to figure out what broke, the display or the controller?

I have been trying to find documentation about the display or the controller but I can't find anything.

I measured the voltage between the red and black cables of the display and I'm getting 51V, so the battery is ok and connected, however the display doesn't switch on.

I have tried to open the display but I can't find a way to "pry it", any ideas?

Besides the red and black, the display also has green, blue, yellow, white and brown cables. I believe white and brown are for external accessories, such as lights.

Is there a way of switching the controller on? I think I read somewhere by jumping the red and blue cable of the display, the controller would switch on? (I have already tried that, jumped red and blue and then pulled the throttle but everything is pretty dead)

If anybody can give some guidance about what the cables of the display do (green, blue and yellow) that would be highly appreciated.

Also, how can I test the controller without a display?

Thank you so much for your help.

 

[Nealh]

Yellow and Green are/should be RX/TX they send comm's back and forth t between controller for compatibility, Blue is/should be 5v switching supply.

Test the controller phase for mosfet damage with a resistance/ohms test.
BlownMosfets.cdr (ebikes.ca)

 

[vfr400]

I think Neal must be missing a bit of sleep regarding that blue wire He spends a lot of time worrying about your ebike problems when he's trying to get to sleep, so be kind to him. The blue wire is the one that powers the controller. It looks like your display has crapped out for whatever reason. It works independently from everything else, so if you have battery voltage on the red and black wires, it should switch on, though if you have a battery fault, you sometimes get voltage from it, but as soon as you draw current, it collapses, so you really need to check the voltage between those wires while you attempt to switch on to see if it holds. If it does hold, the LCD is U/S, if it doesn't, you have a battery problem.

Assuming that it's the LCD that has the fault, you can run without it temporarily while you figure out what to do about it. To do that, disconnect the LCD and bridge the red and blue wires. The LCD connects those two when you switch it on. Sometimes you have to bridge the two data wires as well, which are the yellow and green ones, but don't do that unless you have to. In that mode, your throttle will work and you get get pedal assist level 1.

Brown and white are for the lights. When you do the bridging, make sure that you don't touch the yellow or green wires with the battery voltage, otherwise you kill the controller. Maybe disconnect the battery while you do it, and then short the red and black wires to discharge the capacitor.

 

[bneccs]

Yellow and Green are/should be RX/TX they send comm's back and forth t between controller for compatibility, Blue is/should be 5v switching supply.

Test the controller phase for mosfet damage with a resistance/ohms test.
BlownMosfets.cdr (ebikes.ca)

Thank you for your reply Neal, I'll have a look to the mosfets if the display is blown.

 

[bneccs]

Thank you vfr400 for your detailed reply.

The battery is ok, I haven't tested the controller yet with the recommendations. However there's only one thing I didn't get clear:

Maybe disconnect the battery while you do it, and then short the red and black wires to discharge the capacitor.

I guess you're talking about shorting the red and black in the display side while disconnected from the controller? Otherwise I'll short the battery. However you said with the battery disconnected, so it could be in the controller side with the battery disconnected?

Can I ask you another question?

My motor is Voilamart and I noticed the original controller made the motor quiet while running. The Brainpower one is noisy. Is that related to square and sine waves?

Also there seems to be Brainpower controllers and KT controllers. Even though both controllers have the same colour coded 5 cables to connect to their displays, the connectors have the colours in different positions. Are the KT displays compatible with the Brainpower displays?

The only ones I can find with sine waves are the KT ones though.

Thanks again for all your help.

 

[Nealh]

KT displays only compatible with KT controllers.

 

[vfr400]

Thank you vfr400 for your detailed reply.

The battery is ok, I haven't tested the controller yet with the recommendations. However there's only one thing I didn't get clear:



I guess you're talking about shorting the red and black in the display side while disconnected from the controller? Otherwise I'll short the battery. However you said with the battery disconnected, so it could be in the controller side with the battery disconnected?

Can I ask you another question?

My motor is Voilamart and I noticed the original controller made the motor quiet while running. The Brainpower one is noisy. Is that related to square and sine waves?

Also there seems to be Brainpower controllers and KT controllers. Even though both controllers have the same colour coded 5 cables to connect to their displays, the connectors have the colours in different positions. Are the KT displays compatible with the Brainpower displays?

The only ones I can find with sine waves are the KT ones though.

Thanks again for all your help.

You will have the display disconnected and discarded, so nothing to do to it, The capacitor is in the controller and will hold battery voltage on the red and black wires coming out of the controller to the LCD. Those wires are directly connected to the red and black battery wires, so you can short them on either pair to discharge the capacitor with the battery disconnected.

The Brainpower controller is a relatively cheap square wave one, so yes you get a lot more noise and vibration from the motor compared to a sine wave one, especially at low speed where you can feel the commutation pulses. That's the same with any motor, except that some of the modern Bafangs and the Aikema motors have high reduction ratios, which reduce that effect. LCDs are generally not compatible with other brand controllers. Some functions will work, like the basic switching on and PAS 1 as long as the wires are connected in the correct sequence, but anything that involves communication won't work because they use different protocols.

Kt is the only controller that I recommend unless you're strapped for cash. The extra £30 is well worth the cost considering the much better function you get from it.

 

[bneccs]

You will have the display disconnected and discarded, so nothing to do to it, The capacitor is in the controller and will hold battery voltage on the red and black wires coming out of the controller to the LCD. Those wires are directly connected to the red and black battery wires, so you can short them on either pair to discharge the capacitor with the battery disconnected.

The Brainpower controller is a relatively cheap square wave one, so yes you get a lot more noise and vibration from the motor compared to a sine wave one, especially at low speed where you can feel the commutation pulses. That's the same with any motor, except that some of the modern Bafangs and the Aikema motors have high reduction ratios, which reduce that effect. LCDs are generally not compatible with other brand controllers. Some functions will work, like the basic switching on and PAS 1 as long as the wires are connected in the correct sequence, but anything that involves communication won't work because they use different protocols.

Kt is the only controller that I recommend unless you're strapped for cash. The extra £30 is well worth the cost considering the much better function you get from it.

Thank you again for your reply.

I bridged the red and blue with the display disconnected and nothing happened, then I bridged the yellow and green and nothing happened, then I disconnected the battery and shorted the red and black to discharge capacitors and nothing happened.

I have the feeling that the display needs some interaction from the controller and the controller needs the display to operate. Bridging cables is not making the controller work and the odds of having a display and a controller broken at the same time are very small.

I will just buy a sine wave KT controller and a compatible display and put the Brainpower controller and display where it should be: the bin.

Thank you again!

 

[vfr400]

I have the feeling that the display needs some interaction from the controller and the controller needs the display to operate.

It doesn't. The controller can work independently from the LCD, otherwise I wouldn't have told you to do that. With the red and blue bridged, you should be able to measure battery voltage on both wires when switched on. Did you check that?You need to be sure about what's wrong before buying anything.

 

[bneccs]

It doesn't. The controller can work independently from the LCD, otherwise I wouldn't have told you to do that. With the red and blue bridged, you should be able to measure battery voltage on both wires when switched on. Did you check that?You need to be sure about what's wrong before buying anything.

Yes I did all that, I measured the voltage when the red and blue were bridged and I got 52V.

I disconnected everything from the controller, except the battery, the motor, and the throttle.

I also checked the voltage for the lights connection in the controller when I bridged the red and blue and I got 0V, then I measured the voltage in the throttle (red and black) and got 0V. It means the controller is not switching on.

I have been looking for a good KT controller seller (I'm in Australia), but I can only find KT controllers in Aliexpress. It is hard to figure out what's good and what's bad. Anybody knows of a good seller with quality KT controllers in Aliexpress?

Thank you again for all your help.

 

[vfr400]

Yes I did all that, I measured the voltage when the red and blue were bridged and I got 52V.

I disconnected everything from the controller, except the battery, the motor, and the throttle.

I also checked the voltage for the lights connection in the controller when I bridged the red and blue and I got 0V, then I measured the voltage in the throttle (red and black) and got 0V. It means the controller is not switching on.

I have been looking for a good KT controller seller (I'm in Australia), but I can only find KT controllers in Aliexpress. It is hard to figure out what's good and what's bad. Anybody knows of a good seller with quality KT controllers in Aliexpress?

Thank you again for all your help.

It would be very unusual for the 5v not to switch on when you have battery voltage on the blue wire because the blue wire goes more or less straight to the 5v regulator that gives out the 5v. When the 5v regulator is blown, it normally gives out something, not zero volts, so the first thing I'd do is open the controller and check whether you have the 52v on the pad where the blue wire is soldered, then follow it down any track to verify that the solder joint isn't dry.

Your problem doesn't really add up. Is there something you haven't told us? It's almost impossible for an LCD not to switch on if it has battery voltage. It can happen if a wire is pulled off or shorted, but the chance of any fault in there finding its way to the 5v regulator is very low indeed. I would have expected that whatever fault you have, only the LCD or the controller would be dead. The only exception is when you put battery voltage on one of the data lines. It wipes out the CPUs in both the controller and LCD, but that wouldn't affect the supply from the 5v regulator and the LCD would still flash on when you press the button.

One other thing that I can think of is that you have no ground in the controller, though I'm pretty ssure that the blak to the LCD comes directly from the black battery wire and if you measure 52v between the red and black LCD wires, the black must be grounded. Is that how you measured or did you use the battery black as ground? There is the scenario that if you connect the battery the wrong way round, it blows the shunt, which causes an open circuit on the ground. Only if the LCD's black would be soldered on the inboard side of the shunt would that stop the LCD from working. I can't remember which side it's soldered.

 

[bneccs]

It would be very unusual for the 5v not to switch on when you have battery voltage on the blue wire because the blue wire goes more or less straight to the 5v regulator that gives out the 5v. When the 5v regulator is blown, it normally gives out something, not zero volts, so the first thing I'd do is open the controller and check whether you have the 52v on the pad where the blue wire is soldered, then follow it down any track to verify that the solder joint isn't dry.

Your problem doesn't really add up. Is there something you haven't told us? It's almost impossible for an LCD not to switch on if it has battery voltage. It can happen if a wire is pulled off or shorted, but the chance of any fault in there finding its way to the 5v regulator is very low indeed. I would have expected that whatever fault you have, only the LCD or the controller would be dead. The only exception is when you put battery voltage on one of the data lines. It wipes out the CPUs in both the controller and LCD, but that wouldn't affect the supply from the 5v regulator and the LCD would still flash on when you press the button.

One other thing that I can think of is that you have no ground in the controller, though I'm pretty ssure that the blak to the LCD comes directly from the black battery wire and if you measure 52v between the red and black LCD wires, the black must be grounded. Is that how you measured or did you use the battery black as ground? There is the scenario that if you connect the battery the wrong way round, it blows the shunt, which causes an open circuit on the ground. Only if the LCD's black would be soldered on the inboard side of the shunt would that stop the LCD from working. I can't remember which side it's soldered.

I'm agreeing with you, nothing is making sense. I will just connect the power cables of the display (not the data or blue cables) to the battery and check it it switches on.

Then I'll remove the controller from the bike (which I was trying to avoid) and test with my old Voilamart controller.

Even though I like the functionality of the Brainpower, combining the throttle with the pedal assist, I don't like the noise in the motor. Unfortunately the Voilamart is so basic it doesn't even have assist levels, just full level. When you pedal the bike takes off at maximum power so I even had to disconnect the pedal sensor and just leave the throttle connected to that controller.

The only way to find out what's going on is going to be by opening the Brainpower controller. It is probably a broken cable or something stupid like that.

Thanks again for your help.

 

[bneccs]

I figured out what's going on. The cable colours are different. The data cables are blue and green. The yellow cable is connected to vcc in the circuit board. When I jumped yellow and red the controller started working. The display doesn't work at all. I have attached a few pics of the controller for future reference.

 

[vfr400]

That's very worrying. It's the first time I've seen anything other than blue in hundreds of controllers. Now it means the only way to be sure is to open the controller to check.

 

[bneccs]

That's very worrying. It's the first time I've seen anything other than blue in hundreds of controllers. Now it means the only way to be sure is to open the controller to check.

Yes I agree with you. These things should be standardised. It is a miracle I didn't blow up the controller. If you compare it with a KT controller the cable order is the same but the cable colours are different. On their defense, yellow makes more sense for power than blue for me.

 

[vfr400]

Bikes without LCD or LED control panels often have the two wires on a 2 pin connector so that you can fit your own switch. In that case the most common colours are red and pink or red and yellow..

 

[Cybercatns]

I figured out what's going on. The cable colours are different. The data cables are blue and green. The yellow cable is connected to vcc in the circuit board. When I jumped yellow and red the controller started working. The display doesn't work at all. I have attached a few pics of the controller for future reference.


View attachment 43724View attachment 43725View attachment 43726View attachment 43727

This saved my life. I brought cheap 500w motor kit. It had brainpower may be a replica controller. After 45km M2 display which was shipped with it burned. So I ordered S866 display. It didn't work due to communication failure. Then I searched the whole Internet and didn't find a solution. Finally God showed me this thread. I checked the voltage out puts from the display and got to know the same problem as yours. Now communication failure is gone and all functions work. Thank you so so so so much.

 

[dahoudini]

I figured out what's going on. The cable colours are different. The data cables are blue and green. The yellow cable is connected to vcc in the circuit board. When I jumped yellow and red the controller started working. The display doesn't work at all. I have attached a few pics of the controller for future reference.


View attachment 43724View attachment 43725View attachment 43726View attachment 43727

Hey sorry to be such a beginner here but what exactly do you mean by ‘jumped red and yellow’? Does that mean you put a pin or ‘jumper’ in the yellow slot that connects directly to the red wire slot? I’m having all the same issues and have all but thought I am insane. These dookie brainpower controllers are a hoax. I have the exact same setup and one of the s866 lcd gives me an error 10 and the next 07 and that one runs with throttle. Then another gives me nothing and lastly a fourth gives me error 00. Literally same controller and exact same setup but only difference is the lcd that came with each controller (all s866). Grrrrr

if you could clarify what you did by jumping the red and yellow I would appreciate that so I can continue to work through this madness.