Your CD skips or has audible glitches, or it won’t rip (copy) without errors. You’ve tried the cleaning and polishing technique from my earlier article<\/a> and tried it on a different drive, with no luck. More aggressive action is now required.<\/p>\n First, it’s useful to understand how a CD is constructed and what my repair attempts to do. A commercially pressed audio CD is essentially a thin disc of polycarbonate plastic bonded to a very thin metallic data layer. We’ve all been told to be careful of the underside (shiny side) of a CD, because that’s the side through which the laser reads, but actually the reflective data layer is just underneath the top side of the disk (the side with text and artwork).<\/p>\n <\/p>\n Scratches to the underside don’t damage the data, unless very deep, but they can refract or scatter the laser, causing read errors.<\/p>\n Like a vinyl record, a CD’s data are in a spiral line but a CD is read from the centre to the outer edge. A radial scratch, that runs in a centre to edge direction perpendicular to the data stream, may not cause any problem. A concentric scratch, in a curve parallel to the outer edge, can cause errors even when small and shallow.<\/p>\n