Hello, I have a (1) Sony MZ-R91 and a (2) Sony MZ-NH600. The Sony MZ-R91 will play most discs from the beginning but then gets to about the second or third track and stalls there, not playing anything but repeating the same time on the timer (so its still spinning) untill i stop it. I guess this is skipping although there is no audio. The Sony MZ-NH600 will only play some discs and the ones it does play, it has a similar probelm where it will stall around the 2nd track, but instead of just repeating the stall it will turn off. I would suspect there is some problem with the laser or motor. I have tried spraying compressed air into the MD players to get rid of dust but no difference. I will look for some repair tips online but any suggestions as to what the prob is, and how or links to fixing it myself would be much appreciated. Thanks Alice