troubleshooting LED cube

I have one LED that won’t display red and three LEDs that show faint red when the red is supposed to be turned off. Does anyone have any ideas?

If you look at the board with the power cable pointed at you, the non-working red would be in bottom row, left column, 2nd vertical slice back (1,1,-2 coordinates. One of the faint LEDs are in the bottom row, left column , 4th row back (1,1,-4) The third LED is in the last row back, the bottom slice, 3rd from the left ( 3,1,-4). I think they all share a red current sink.

All the other lights are working.


It was a bad LED. I swapped in a different LED and all colors now work. The same 3 LEDs show a very faint red when turned off but not enough to worry about.