Sega CD Model 1 Repair...

[mcnougat]

I have a Sega Genesis Model 1 connected to a Sega CD Model 1, and the Genesis part works fine.

The Sega CD loads up the bios and prompts for a new disk, and the disk tray opens and closes, but there is no spin-up. The access light blinks forever, sometimes it spits the CD out again.

Sometimes I hear a clicking noise as the tray opens or closes, or when it just closed.

I've already tried cleaning the lens with 71% isopropyl alcohol but that hasn't worked.

What next?

Edit: Thanks in advance.