I searched the archives but found nothing definitive.

Stock system with factory 6 disk changer. The head unit says "NO CD" when I push the CD button. I have 2 cartridges and they both insert and eject correctly so I know the changer is getting power. Any suggestions?

thanks,

Randy
'94 E500

Here are some quick thoughts:

Have somebody sit in the car and select the CD input while you listen to the changer. See if makes any noises such as loading the disc, spooling up the RPMs, searching for the index. If you don't hear a thing, then maybe it's an electrical connection.

If you do hear it trying to do something, use some canned air on the laser assembly - some dust may have built-up on the optics. The laser units don't last forever - usually around 5 years.

If you think it is electrical, disconnect the CD changer and test the input plug into the changer with a volt meter. With some trial an error you probably should get some voltage jumps as you press the change disk button, skip track, etc. I don't think MBZ started using optical links until the late 90s, so your "should" be electrical. This should help rule the head unit as the problem.

Before going to MBZ, you could stop by Circuit City, etc., and have them check it out too - they probably won't charge you since they assume you'll replace with a change from them. I don't know MBZ, but the Alpine changes seemed to be "the" universal changer which worked in alot of cars. Called the CD Shuttle, the cost around $250-$300 and sometimes you need an adapter which costs around $75. I'd expect to pay around $400 to $500 if you opt to have Circuit City, Best Buy, Car Toys, etc. put in an after market unit. Just a benchmark to compare the replacement part cost with.

Thanks for the reply John.

The unit loads all 6 disks one by one and then says "no cd" so it must not be able to read the disks. I think this weekend I will pull it apart and take a look. If there is not an obvious problem its time to leet the pros handle it - I'm having a hard time without my cd's!

Randy
'94 E500

Just a thought are you putting in the cd's upside down?
I don't know if this car is new to you.

Good point! I'm pretty sure I have the labels up but I will double-check. I've had the car almost 2 years and its the exact same changer as in my Porsche that I've had now for 6 years, but you never know. I've been known to do stupid things before! Thanks for the thought.

Randy
'94 E500

It sounds like unit is cycling through each cd holder, loading the respective CD and then looking for the first track or index on the CD. Most changers cycle through the magazine like this, and they know if they've found a CD when it can read the first index on the CD. If it can not read anything, then it assumes the tray was empty and proceeds to the next tray (looking for a CD, and so on).

In your case, it sounds like the changer is loading the CD, tries to read the first index, doesn't read anything and proceeds to the next CD. It could be an alignment problem (laser isn't tracking properly), a dirty lens, but I'm still leaning towards the laser being burned out.

If it's an alignment issue, usually the changer will try & try to read the CD and you can hear some high pitched digital type noise coming from the changer - you have to listen very, very closely to the changer unit. Most integrated changers report back "ERR" on the head unit display if this happens.

If it's a dirty lens, problems are usually intermittant and it doesn't happen all at once. Dust builds over time, condensation helps to bond the dust to the laser, etc. If this has been happening over time and getting progressively worse, it could be just dirty optics/laser.

If the problem started all at once - think of it as a light bulb burning out. 3 to 5 years was the normal life span of a CD laser in the early to mid '90s.