An easy way to figure out of the laser is dead-- open the lid, use something small and pointy to hold the CD lid "door" switch closed, and hold a CD at an angle above the spindle and laser so you can see a reflection of the laser eye in the CD.
Power up, and press RUN. If you see a red laser from the eye in the reflection, the laser itself is working. You've got another problem (could be laser calibration, stuck gear, sled, motor, limiter switch, etc).