no sound from alpine cda-9831?

all channels are wired correctly and remote ant wire is hooked up.  the unit powers up fine and sound comes from the radio am/fm, but when i try to play mp3s or cds, there is no music.  it shows the file playing, just no sound.  any help here?  this unit is brand new and i need this thing working by wednesday morning if possible.  thanks!

Today is wednesday and you posted your question today at 1.52am saying you "need it by wednesday" and not "need it by today noon". Did you mean you need this by today or next wednesday? In any case it looks like you have a defective HU. Try more than one CD (preferably an original factory pressed CD) to make sure your CD is good. If you can listen to your Radio from the HU then your wiring and speakers are good.   If only the CD and mp3 does not play even though you see the CD playing on yoru display, the only thing I can figure out is a partially defective HU. If you can take it back to the store you purchased for an exchange, you can have it today (wednesday). If you have to ship it to somewhere, the sooner you ship it, you might get it by next wednesday. Good luck and let us know how you fare with this issue.

yes, that right. The blue "remote antenna" power wire gets approximately +12v only when the radio is on. So your external amp was on only when the radio was on and no voltage when in CD mode. if you connect the remote-turn-on wire (which is usually also blue) like   geepherder mentions, that should work. I was not too clear when I read "...and remote ant wire is hooked up..." have fun with your CDs and mp3s.