Re: AppleCD Audio player misbehaving

[Rubywand <rubywand@swbell.net>]

Janice Olsen writes ...
> 
> Help (please).   I am a relative newbie and am having trouble
> with the AppleCD audio player on my PowerComputer Mac clone.
> I was able to play audio CDs last week on my external speakers
> (plugged in, of course, to the back of the CPU).   Now, all of
> a sudden, audio CDs won't play through those external
> speakers.  (I can get sound from the speaker plug on the front
> of the CD player itself).  Oddly enough, all the other stuff
> WILL play through the external speaker outlet in the back, for
> instance, the PowerComputing tutorial CD -- with sound -- will
> play from the speakers when plugged in the back.   Also, the
> regular "alert sounds" play through those speakers plugged in
> the back.  Why no sound from audio CDs in the same CD player?

> I'd appreciate anyone's suggestions; please e-mail me, as I am
> not able to check this newsgroup very frequently.   Thanks.


     Okay. In case someone else runs into a similar problem, I'll do a
post too.

     The difference between system sounds, games sounds, etc. and music
played from a standard music CD is the source.

     System sounds and sounds from most programs are produced 'in the
computer'. CD music and any other sound played directly from a CD disc
sound track comes from the CD through the CD-ROM player. This explains
why, whatever happens in the computer, the music can be heard via
headphones or speakers plugged into the jack on the player's front
panel.

     CD music typically comes from the CD-ROM player as plain Left and
Right Stereo audio. The computer Sound system's main job is to accept
the audio and send it out to the speakers or amplifier. For example, in
a modern PC, the CD-ROM audio will usually go through an internal Stereo
cable to a plug on the Sound Card. The Sound Card takes care of sending
the CD sound and any system, game, etc. sounds to the speakers or
amplifier.

     If CD music discs suddenly stop playing just through the
back-of-computer speaker jacks, the culprit is likely to be a loose
connection from the CD-ROM drive's output to the Sound system. I do not
know how a PowerMac is set up; but, a reasonable guess is that some
internal cable plug is loose.

     Another possibility is a broken solder connection. Since,
evidently, both channels are missing, if there is any kind of broken
solder connection, it is likely to be in the Ground line coming from the
CD-ROM player. Other possibilities include a loose IC-- such as some
interface IC which accepts input from the CD player, or, even a blown
circuit component.

     A decent fix try is to open the case and find the cable going from
the CD-ROM player to wherever. If one end is obviously loose, replug it.
Otherwise you may have a 'dirty' contact which can be cured by unpluging
and re-pluging the cable at each end.


Rubywand