Sounds like the laser isn't tracking properly which could be (most likely, but not exclusively) due to:
1.) the lens is dirty, unlikely, but if you can get to it, clean with a q-tip just barely dampened with alcohol, or
2.) the transport rails (that carry the laser pickup carriage back and forth) are dirty (more likely) and or the lubrication is dried out. Clean with a q-tip dampened with Ronsonal lighter fluid (naptha) or if you cant get that a little gasoline or kerosene, and wipe with a dry q-tip. Try it first without adding any lubricant. If it works leave it alone. Otherwise, dampen a q-tip with some light sewing machine oil or similar, and lightly (and I do mean lightly!) wipe th rails with it.
If none of this works, the problem may be elictrical rather than mechanical, but that would be rare.
1.) the lens is dirty, unlikely, but if you can get to it, clean with a q-tip just barely dampened with alcohol, or
2.) the transport rails (that carry the laser pickup carriage back and forth) are dirty (more likely) and or the lubrication is dried out. Clean with a q-tip dampened with Ronsonal lighter fluid (naptha) or if you cant get that a little gasoline or kerosene, and wipe with a dry q-tip. Try it first without adding any lubricant. If it works leave it alone. Otherwise, dampen a q-tip with some light sewing machine oil or similar, and lightly (and I do mean lightly!) wipe th rails with it.
If none of this works, the problem may be elictrical rather than mechanical, but that would be rare.