My sister's Aiwa mini system's cd player quit reading discs. I had a Yamaha player do the same thing back in the late 80's and a Pioneer do it in the early 90's. Neither player was very old at the time but both were out of warranty as is my sister's. My question is: Has anyone here had their cd players repaired to correct this problem? What is the culprit? Is it worth the money or just buy a new one?