Problems with new UKC1 display with Sabvoton 72100 controller

cbrady1981

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I'm trying to bench-test my new kit (link) before installing on the bike, but having problems getting the display and controller to power on. I've got the controller wired up to a 64V battery pack (20s Lifepo4's).
Holding the power button for a couple seconds will turn on the controller, but not the display, and the controller turns off immediately as soon as I release the power button. I've been able to hold the power on and communicate with the controller via the MQCON software, it shows that the brake & throttle inputs are working, was even able to spin the motor - but only as long as I'm holding the power button down. I've plugged & unplugged everything many times.
I'm guessing the display is supposed to keep the "ignition" on to the controller, and that's not happening. Anybody have any experience with this display? Does it need 72V to function (the kit lists 36-72V)?

Thanks in advance
 

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I'm trying to bench-test my new kit (link) before installing on the bike, but having problems getting the display and controller to power on. I've got the controller wired up to a 64V battery pack (20s Lifepo4's).
Holding the power button for a couple seconds will turn on the controller, but not the display, and the controller turns off immediately as soon as I release the power button. I've been able to hold the power on and communicate with the controller via the MQCON software, it shows that the brake & throttle inputs are working, was even able to spin the motor - but only as long as I'm holding the power button down. I've plugged & unplugged everything many times.
I'm guessing the display is supposed to keep the "ignition" on to the controller, and that's not happening. Anybody have any experience with this display? Does it need 72V to function (the kit lists 36-72V)?

Thanks in advance
it seems that this post did not had interactions since 2020.
I have the same issue after installing the wrong front light (Battery 36V, out put controller for the light is 36V) the light I installed was 6V so it burned right away, and since then I can't turn on the Controler directly from the display ON button. Everytime I want to use my Ebike I have to turn off the battery and then Battery on to automaticly start the UKC1 display. is some one had explanations or a remedy...?
Thanks in Advance
 
If the light connected to the display, then the most likely problem is the display itself is internaly damaged. They usually have transistors that switch on power when hte power button is pressed, and that switch on hte light / backlight when the light control is turned on (if it has one).
 
If the light connected to the display, then the most likely problem is the display itself is internaly damaged. They usually have transistors that switch on power when hte power button is pressed, and that switch on hte light / backlight when the light control is turned on (if it has one).
Thanks a lot for your reply!
Now I have the correct Light (6V-45V Range), it is fed from the controller where is connected to a permanent 36V output designed to the "Headlight".

as I said I had to turn the Battery ON then Automatically the Display turns ON without even hte power button. I use the bike as it has no problem, all settings are working except the Headlight Symbol not appearing. one can notice that we can turn the display OFF once hte power button, but not on except from the Battery power button.

If i follow the idea of a burned transistor, will it be in the electronic where the power button is with +/-/M or in the display?
just to see if it is worth to consider the feasibility of fixing this issue, if it is worth or not to look for solutions to fix it, or there is more thinks I should know about.
Thanks you in advance.
The best,
 
First: Does the system work normally without the headlight connected at all? Or does it operate exactly the same either way?

If it works without the light connected, then the light is drawing too much current for the electronics, and would need to be wired to your battery separately from the controller/display, via it's own switch you could mount on the handlebars or elsewhere.



If it's the same either way, then:

If the transistor itself (inside the display) was failed, it would not be able to turn on, or else would not turn off. Since both functions do work, it's more likely to be in the controlling electronics that are also inside the display.

Even that is a bit odd, since the same things are used to turn it on as to turn it off.


NOrmally the way these are designed, the main battery power B+ and ground goes to the controller, but is only powering the FETs, not the brain/etc. Then wires for the B+ and ground go to the display, which power that.

The power button on the display just commands the sleeping display brain to wake up, which then turns on a transistor that passes B+ to a "lock" or "KSI" wire that passes B+ back to the controller's brain power supply, turning on the controller.

If the headlight is wired at the controller, and turns on with the controller (rather than with the display backlight control), then any overload from the wrong light would have happened to the entire "lock" / transistor circuit. Normally that only damages the actual transistor, usually blowing it open so the controller can no longer turn on, but sometimes failing shorted so the controller is always on even if the display is off.

Since all the logic / etc for controlling the transistor is in the display, it is most likely that the display itself is causing the problem you see, and replacing that would probably fix the issue. You might be able to fix it by replacing the transistor inside the display, but since the behavior is not the usual for such an issue, it might be more complex.

If the headlight is wired at the controller and only turns on wiht the display light/backlight control, then there is *probably* a separate wire from controller to display for this, and a separate control transistor/etc in the display that handles that. But a failure in this circuit should not affect anything else, so it's unlikely to be setup this way.

Same for if the controller has it's own transistor to turn the headlight on, commanded by the controller brain after teh display brain tells it (over serial data lines) to do so.


Why exactly the display (or system) would be damaged in the way that it is from the headlight problem, I can't say, without knowing the complete circuit info for the controls, transistor, and headlight wiring inside the controller and display.
 
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