Number 316 - September 2009

CD-Rs Harder To Read Than Standard Discs
Patrick Marshall, Seattle Times
Q: I received a CD from someone and I couldn't read it. Windows Explorer and Record Now both reported it as a blank CD-R with 703MB available for recording. A replacement CD didn't work either.    I found a computer that would read the replacement disc, but not the first one.    I tried both discs on an old computer and it could read both.    Visual examination suggests they are not recorded strongly (shade very faint), thus a drive with weak reading ability may not read them. Any ideas?    A. Since you refer to "shading" on the disc it seems you know about the difference between commercially produced CDs and "burned" CDs.    Just in case--and for the benefit of readers who may not know--I'll go over the difference anyway: Commercially produced CDs are produced like old fashioned vinyl records, with a machine cutting pits and grooves in the plastic that are later "read" by a laser scanning the surface.    Burned CDs created on a PC employ a different process. With burned CDs, lasers create a pattern in a layer of dye on the disc. The pattern in the dye is later read by the laser.	Commercially produced CDs can be read by virtually any CD player, unless they are too scratched or the CD drive is too dirty. With burned CDs, unfortunately, the results are much less certain.    The dyes used in a given brand of recordable CDs work better with certain drives than others. So the CD you burn on your computer may or may not be readable on someone else's computer or on a car CD player.    The first thing to do is to make sure that the CD drive in your computer is clean. You can try blowing a little compressed air into the drive to clear out any dust.    If that doesn't work, you might try a cleaning disk, available at your local electronics or music store.    If the drive is clean and you're still encountering the problem, it may just be that your drive doesn't work so well with the dyes used in certain brands of discs.    Finally, it is possible the laser in your CD drive--or in the drive that burned the CD--might be slightly out of alignment. In that case, results won't improve until the unaligned drive is replaced.
Number 316 - September 2009