new kt controller doesn't work

[alexscard]

Hi, my 72V 50A KT controller has arrived. Today i installed it on the bike but it doesn't work. The display doesn't even switch on.
The voltage between the two poles of the controller's wires is strange, it changes according to where i try to measure it/ even with the time. I attach some video and a picture to show the situation(it's all messy 'cause i'm just trying to see if it works for now)

https://photos.app.goo.gl/2n72Qz6SopaRFGxi8
https://photos.app.goo.gl/e7WU5kfRwdc1JVum6
https://photos.app.goo.gl/MCZMkrFD3st93Njr5

any help is appreciated :thumb:

 

[alexscard]

Hi, my 72V 50A KT controller has arrived. Today i installed it on the bike but it doesn't work. The display doesn't even switch on.
The voltage between the two poles of the controller's wires is strange, it changes accordingly to where i try to measure it/ even with the time. I attach some video and a picture to show the situation(it's all messy 'cause i'm just trying to see if it works for now)

https://photos.app.goo.gl/2n72Qz6SopaRFGxi8
https://photos.app.goo.gl/e7WU5kfRwdc1JVum6
https://photos.app.goo.gl/MCZMkrFD3st93Njr5

any help is appreciated :thumb:

p.s. i bought it new from the official kt store from aliexpress, they told that they test them before the shipping, but who know..

 

[jm1090]

Hi, my 72V 50A KT controller has arrived. Today i installed it on the bike but it doesn't work. The display doesn't even switch on.
The voltage between the two poles of the controller's wires is strange, it changes accordingly to where i try to measure it/ even with the time. I attach some video and a picture to show the situation(it's all messy 'cause i'm just trying to see if it works for now)

https://photos.app.goo.gl/2n72Qz6SopaRFGxi8
https://photos.app.goo.gl/e7WU5kfRwdc1JVum6
https://photos.app.goo.gl/MCZMkrFD3st93Njr5

any help is appreciated :thumb:

p.s. i bought it new from the official kt store from aliexpress, they told that they test them before the shipping, but who know..

Could you please link that official seller on aliexpress ?

Also, could you take a look inside at which MOSFETS are mounted ? Are those IRFB4110 ?

Thanks !

 

[alexscard]

Hi, my 72V 50A KT controller has arrived. Today i installed it on the bike but it doesn't work. The display doesn't even switch on.
The voltage between the two poles of the controller's wires is strange, it changes accordingly to where i try to measure it/ even with the time. I attach some video and a picture to show the situation(it's all messy 'cause i'm just trying to see if it works for now)

https://photos.app.goo.gl/2n72Qz6SopaRFGxi8
https://photos.app.goo.gl/e7WU5kfRwdc1JVum6
https://photos.app.goo.gl/MCZMkrFD3st93Njr5

any help is appreciated :thumb:

p.s. i bought it new from the official kt store from aliexpress, they told that they test them before the shipping, but who know..

Could you please link that "official seller" on aliexpress ?

Also, could you take a look inside at which MOSFETS are mounted ? Are those IRFB4110 ?

Thanks !

https://kuntenge-bikefactorystore.aliexpress.com/store/911380051?spm=a2g0o.detail.1000007.1.233f54b7xPRIgd

 

[alexscard]

edit: double

 

[docw009]

The display doesn't even need a working controller to power up. All it needs is power on its power leads. You can see that if you have the 5 pin flat connector, on the red and black leads.

You have power at the battery leads, and you don't measure that when you test at where the controller attaches to the battery? Think about why that happens.

 

[alexscard]

The display doesn't even need a working controller to power up. All it needs is power on its power leads. You can see that if you have the 5 pin flat connector, on the red and black leads.

You have power at the battery leads, and you don't measure that when you test at where the controller attaches to the battery? Think about why that happens.

on the controller's power wires as i said there are around 20V that i don't know why the wave over time during the meausure between 15 and 20+.
What should be the voltage between the + - of the controller? the same of the battery?

 

[Comrade]

What should be the voltage between the + - of the controller? the same of the battery?

Yes.

https://photos.app.goo.gl/MCZMkrFD3st93Njr5

You need a bigger soldering iron. And maybe even flux. That's a very bad connection.