NXT ERT display: my attemp to fix it

Doctorbass

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Note;
  • I have no wirring harness for connections to the BAC8000
... yet...
  • This BAC8000 apparently is locked from ERT and it is not possible to reprogram it unless i get help from Alan?
  • I did not attempt to connect it with wrong harness, ex: litespeedbike eggrider harness
... yet
  • It overload the USB input of my computer when i connect the micro usb of the inside arduino board to my PC


I suspect that it has been plugged (by the previous owner) to the wrong harness and the wrong voltage at input blown something on the pcb.

I decided to open it and as well to also show you what's inside as Alan Hu does not respond to anybody that need help so ... why not to reveal it once for all! :

I found a arduino MEGA2560 PRO board inside that is connected to a display NEXTION touch screen model : NX4024K032_011

Arduino: https://robotdyn.com/mega-2560-pro-embed-ch340g-atmega2560-16au.html
Display: https://nextion.ca/datasheets/nx4024k032_011/

On the Arduino, there are two voltage regulator that i suspect maybe one to be blown. one is 5.0V 800mA and the second one is 3.3V 800mA, both model AMS1117.

The 5V input of the NXT is showing 7.58ohms which at 5V is not normal as it's like 650mA of current draw

The 5V input of the HIGO connector is directly connected to the 5V output of the AMS1117-5.0V.
The 5v output of that regulator goes to the input of the AMS1117_3.3V regulator.
BUT! the 5V is showing 7.58 ohm so i suspect that the 3.3V regulator might be ok and the 5V regulator is just blown.

It seem that the Eggrider connector is not only different voltage but also have teh RX and TX reversed compared to the NXT

HIGO Pinout.pngI got a BAC8000 and a NXT display( the "X" shape model) and it seem that the display is broken.

I will replace it and see if it can work.

Coming next: DIY harness NXT to BAC8000.

Doc
 

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Hi Doctorbass. I bought a Nxt used. Unfortunately, I simply connected it because it has the same connection as my Eggrider without checking whether it works without damage. I have a Bac 800 /Bac 855 Controller, a 48v battery and a Gmac motor and Eggrider display. When connecting it sizzled briefly... The processor on the Mega 2560 board is probably burned out or what kind of component it is (the black square one with the many pins). Do you know if I can just replace the Mega 2560 per board and it will work again? Or is something like firmware stored on the board? Unfortunately I have no idea about these boards. Did your repair work? what exactly did you do
 
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