1) The circuit board only works, if all 4 outputs are used. As soon as only 1, 2 or 3 output lines are used for lighting LEDs, it does not work. How do we have to modify the electronic circuit board that it also works if only 1, 2 or 3 output lines are connected? 2) Short circuit behaviour: If one SINGLE output is on short circuit THREE LED-output lines fail. This is valid for each output to be on short circuit. The final electrical parts heat up massively and will most likely burn. We need to have the electronic circuit board modified, that each of the four output lines can be independent and permanent on short circuit, without harm to the board.
I am very grateful for a response on how to achieve this.