CD/DVD Changer No Sound!

I have a 2007 Touring AWD with most of the bells and whistles.  It has the REV Radio with Sirius, the single CD in dash and also the 6-disc cd/dvd changer.  Everything works from a controls standpoint for all modes, AM, FM, CD, Sirius and Changer, but no sound can be heard from any disc being played in the 6-disc.  The car does NOT have the DVD screen and no headphones or remote came with the vehicle.  Has anyone else experienced this? or better yet, does anyone have this setup and it does work?

I have an 07 as well.  I did get a DVD screen installed but I did have the 6 disc changer working before it got installed.  You load a disc and then you have to hit the "mode" button until it displays "ext-aux" (or maybe 't's "ext-dvd"?).  In any case, you are able to load 6 discs into the changer while listening to the single cd player (or am or fm for that matter)...so it doesn't switch automatically when you load a disc into the 6 disc changer.  But you have to hit the "mode" button until the "aux-" shows up. 
 
Hope that helps...

Thanks Batavia.  I have pressed every button, played with every setting (I'm a network engineer so I have to play with everything) and nothing.  I had it at the dealer today and they scratched their heads.  They replaced the changer to no avail.  I suggested maybe it is the head unit that the changer connects to, but that seemed to go over their heads.  I haven't seen how everything interconnects, so perhaps that wasn't truly a valid suggestion.  Everything functions for controls, just when it's on EXT-DVD, no sound at all.  They suggested that you had to have the DVD screen installed and/or it only played through the wireless headsets and controlled by the remote, none of which came with the car.  I said, and fortunately they agreed, that it made no sense to have a six-disc changer and not be able to use it except for wireless headsets and with a DVD screen.  Fortunately the single in-dash player works and we've got the 1-year of Sirius, so it's not really detrimental...but it's there and I want it to work!

if you need the the headphones and the remote i have them for sale from my 04 pac never used pm me

You definitely can play a DVD without the screen, remote, or headphones.  I've tried it myself before the DVD screen was installed.  So you should hear audio even though you don't have a screen to see the video.  Both decks play DVDs, CDs and CD-Rs.

I also thought it might be the cable.  Either it was not connected (at the amp) or it's faulty.  Maybe they can try another cable?

Also, if they replaced the dvd changer, then it pretty much points to the amp.  Sounds like the amp needs to be replaced.  That input may be faulty or unconnected (or loosely connected).  I have no idea what the wiring harnesses look like.

I'm a hardware engineer so that's my 2 cents.

It's nice to have both decks working.  That way the kids can listen or watch on one deck and I can have my mp3 disc on another without constantly swaping discs.  Since they're on different decks, they continue where you left off...so I don't keep hearing the same first 5 kids songs every thing I get in the car.  The headphone option allows the kids to watch a DVD on one of the decks but allow music to come thru the speakers from the other deck (or am, fm, etc).  Great for those long trips.

Good luck....