Removing the intensity didn't help and it works just the same with ground connected or disconnected.
Can I somehow check if the ground on the LED matrix is broke? I think I remember that all columns used to work
Espruino is a JavaScript interpreter for low-power Microcontrollers. This site is both a support community for Espruino and a place to share what you are working on.
Can you try removing
disp.intensity(0);
? I guess that could be doing something strange.Also, you're sure that the GND pin is connected?