I need some info on a Sega CDX

[understatement]

I got a CDX in a load of stuff but the wrong PSU was used on it so it didn’t power on. I replaced the fuse on the power board now it comes on and plays Genesis games but not Sega CD games but what I noticed when plugging in my working CDX (after testing the nonworking CDX) that even with the power off as soon as you plug it in, the CD (if there is a CD in it) will do one full rotation (it even works when putting batteries in) but the nonworking CDX does nothing when plugged in or batteries are put in. So what I need to know, is that a common thing when the laser goes out? Does the CD not spin at all or does it spin and just not read the CD?

To me it just seems more like the motor or no power is getting to that section of the board like another fuse is out.