How do i fix my gemin CDm 3700g so that it reads my CDs

I would go to radio shack or some electronics store and buy a can of compressed air that comes with a straw taped to the can. Plug the straw into the nozzle and open the CD drive and blow the air into it while moving it back and forth in the slot to blow as much dust as you can away from the laser head and surrounding areas. That should clean the laser head and allow it to read properly unless something is wrong with it. I would try that on any CD/DVD drive before any other steps. When they get dusty, they can't read.