L293D motorshield with batteries doesn't power Arduino Recently I came across a video about a guy building a remote Bluetooth-controlled Arduino car and I was quite amazed. So I decided I wanted to build it too. I have no Arduino or electronics experience at all other than being an IT professional.
So I bought the parts he used in the video (he advised a knockoff Arduino in the description).
After putting it all together the motors work through Bluetooth (yay!). But the issue is that the batteries connected to the motorshield don't give power to the Arduino at all (because the lights don't turn on).
When plugged in the laptop with the USB cable the Arduino gets powered and the motorshield light turns on just a bit, but not enough to make the motors and Bluetooth work.
So in short:
USB powered: Arduino works, motorshield light barely turns on, motors don't work, Bluetooth lights go on, but is not emitting a signal.
2x 18650 battery powered: motorshield light shines bright, Arduino doesn't work, Bluetooth lights don't flicker.
Both: everything works.
So for some reason, the batteries connected to the motorshield don't power the Arduino.
Video used:
https://youtu.be/Q36NbjPMV5k
Circuit diagram:

Knockoff arduino:

L293D motor shield (I'm aware that the ground of the power isn't plugged in)

Parts used:

Geekcreit UNO r3 ATmega16U2 AVR
L293D motor shield
Geekcreit HC-05 bluetooth
4 TT motor
2x 18650 3,7-4.2v 2200mah batteries

I really don't know what I did wrong, since I followed the video and did exactly what the person did. Maybe the batteries aren't powerful enough?
The problem was that the 2 pins on which the jumper sits, the jumper or the board was broken (idk exactly). I might've caused that myself by turning on the batteries + powering it through usb at the same time.
I bought a new L293D board then made sure I didn't connect usb power to the arduino while the L293D was sitting on top of it. I uploaded the code, then disconnected the usb, put the L293D on top, powered it all and it works like a charm!