Sega CD drive motor isn't running

I bought a used Sega CD Model 2 a long time ago, and finally got to replacing the optical pickup, which (I thought) was the reason it wouldn't read discs.

So I swap out the pieces, put it back together, and now (and maybe before, I'm not 100% sure) the motor that spins the disc isn't working. I can't see anything necessarily wrong, but I'm not a big pro at this in the first place.

Any suggestions?

 

Big smd fuse at the underside of the board? There are several fuses, som on top side and some on the bottom. Not all will cause complete power loss.

 

Are you sure the optics are good and somewhat calibrated?
The disk will not spin if the laser can't get a focus lock.