I have a Yamaha CDX 550 player that is failing to read about a quarter of the redbook discs that I throw at it. It isn't having any problems with CDR discs. Any ideas? Is there an adjustment I can make that might fix this behavior?

I tried adjusting the potentiometer at the base of the lens assembly about five degrees counterclockwise. Now the player is reading nearly all the discs, and is also running more quietly. There are still a couple discs that it is having trouble with.

OK, not trying to be a smart-a$$, but what did you adjust? Or did you just randomly tweak a control? :music: Is it laser intensity? Increase or decrease? Inquiring minds want to know! :thmbsp:

Yes, that's the ticket: laser intensity. I remembered after posting that I did that once with another CD player and it worked. You have to first mark a dot on the pot so you know where you started from, and then turn the pot in very small increments, then test right after to see if there is any improvement. This improved the reading ability on all discs, and now only 1 out of about 20 discs that I tried is not reading. By the way, don't try this at home.

Sorry to go off topic for a moment but what is a Redbook CD? I've heard the term but am clueless.

By the way, don't try this at home. Of course not! BTW, another thread on this topic forming here (http://audiokarma.org/forums/showthread.php?t=85400).

Sorry to go off topic for a moment but what is a Redbook CD? I've heard the term but am clueless.

A Redbook CD is consumer audio standard 16bit/44.1khz CD's. These are the ones you buy at a music store, online, etc... Redbook is this standard of 16bit/44.1khz.