Why is my Ps2 Slim discs not spinning when the parts are new?

I have a Ps2 Slim and it’s not spinning discs. I replaced the laser (motor) and spindle. I held down the sensors which tell the system if the lid is open or not and still no spinning. The laser does move and work. I also replaced the clock battery. I’m at a loss here. The main reason discs do not spin is due to laser, sensors or spindle. Which all are now new. What else could the problem be if not those?