The sad thing with CD players is when the LENS reader or the laser inside goes, there is nothing you can do, except take it to an expert on electronics. But 90% of the time, it is cheaper to replace it outright. If it is the EYE (the reader) or the laser, you should replace unit, unless you can get warranty on it.
**Working PART-TIME for Carjunky for a while, Please bare with me =)**
Aussie owned parts & Auto Electrical parts supplier
http://www.motolec.com.au