Just as the title says, really. The laser beam doesn’t touch the CD, so it’s not like a big scratch on a record that can guide the needle back into the previous groove.
As I remember it, as the CD spins the laser beam moves at a constant rate from the centre of the disc towards the outside, with the spin speed of the disc being adjusted so that the linear scan rate remains constant. So why does a big scratch confuse this process and keep the laser beam reading the same little segment of disc over and o isc over and o isc over and o isc over and o isc over and o…?
Am I missing something? Do CD players tell the laser beam to “back up” a little to re-read an area if they encounter errors or something?
It should not cause problems. Brasso has a very fine polishing grit in it, which is just what you’d need to make a clean repair. Because of the fineness of the grit, however, it could take a very long time.
Be carefull not to scratch the label side of the CD while polishing, and polish radially - from the rim to the center and back, then turn the CD a tad, rim to the center and back, etc.