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Sondors X - display not powering on, no assistance SOLVED


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I bought a Sondors X about two years ago. I've ridden about 1000 miles on it.  It's the model with 48V 17.5Ah battery and I think 20A controller. The display is the square KD51C version.
Yesterday morning the display just didn't power on and there is no power going to the motor. I can hear a rapid clicking sound coming from inside the display when I'm trying to power on the bike with the power-on button on the handlebar control. The battery is about 75% charged so there definitely should be power available (the battery indicator on the battery itself shows 3 out of 4 lights and the night before, when the bike was working perfectly, the display showed 3 out of 5 bars).

Do you have any idea is it the display or the controller that has gone wrong? I've tried to disconnect everything, let it rest for a while and then re-connected everything with no luck. Is there anything else I could try?

Edited by 0401365
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On 2/15/2021 at 6:19 PM, Reddy Kilowatt said:

I’d start by checking for voltage inside the controller to LCD’s, HiGo connector with your multimeter, to see if power is getting to the LCD. Should be low voltage because it’s only a control signal. Have you tried eliminating the LCD from the circuit by replacing the Higo connector cap that you removed to install the LCD when you assembled your Sondors? If your Sondors does regain basic function, the problem is probably the LCD. 


Holy crap it's alive! I unplugged the display, plugged in the Higo cap and voila, there is power! Thanks Reddy! 

Now I just need to replace the display... Any suggestions besides sondors.com (which I for whatever reason think will take ages to arrive if I order from there)?

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  • 0401365 changed the title to Sondors X - display not powering on, no assistance SOLVED
  • 2 weeks later...

Bike keeps dying. Display fine but power all gone, pedal and throttle and in all speeds. Battery at 4 bars so it’s not that. Bike is Fold XS bought last October. Got a replacement controller from Sondors in December which seemed to fix the same problem but it has now returned. I have ridden it 415 kilometers from new.

Checked all the connections last weekend and all seem good. Please help

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Just back with shunt installed. Same thing - rode about one mile with power, then dead! Had to pedal home with no power. As usual, power returned just as I was parking the bike back home!

Tried switching power off and on again while power was out but it made no difference.

This seems exactly the same as in October/November before I received the new controller.

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Thanks, Reddy. Will do. 

It seems almost exactly like the controller fault that the bike had at the beginning. I tried switching on and off but that doesn’t make a difference. Also “folding” but that doesn’t bring it back either. I do wonder about the motor as it has always been noisy - sort of like an old electric tram, but I am probably the only one old enough to remember the noise they made!

WHere/how do I look for power with the multimeter, please?



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