My laser doesn't work

I tried to understand what is the problem, and maybe i have the solution too, but firstly I want to be sure of what I'm fixing, before I take another laser that costs money ☺️. The CD doesn't spin, but it seems that this is due to a lack of power coming from the mother board. On the cable that comnects the mother board to the optic group there is a little black dot. Chatgpt says that it is a burn caused by some sort of electricity malfunctions.

Can anyone help me?