Mach 460 'CD ERROR'

Discussion in 'SN95 4.6L Mustang Tech' started by HurricaneJesus, Sep 22, 2010.

  1. (Sorry this is so long...)

    Back from the dead. I have a new theory I thought I'd share for those masochists out there still using the CD6.

    The day after I got the car out of storage I took the radio out and had another go at the 6-disc changer and, like I said, have a new theory. Interestingly, the bolded text above hints at what I believe is "a" problem if not "the" problem.

    I went through the same process of removing the CD changer from the radio, removing its cover and inspecting it. I plugged the two connectors back in but left the changer sitting atop the radio chassis and went back out to the car to do some checks in situ. I noted again that the changer seemed to work fine in this configuration. It took a few cycles for the mechanism to achieve proper initialization (it had been left in a truly screwed up state) but once initialized it seemed to load, play and eject CDs from all 6 slots.

    I watched the mechanism more closely and think I made a significant finding. First some background:

    The changer mechanism is mounted to the changer chassis with four (4) rubber mounts. The mechanism is suspended with 4 springs, one at each corner and together these springs and the rubber mounts help isolate the mechanism from vehicle bumps and vibrations that would otherwise cause skipping. The changer mechanism (already noted as being fiendishly complex) goes through a crazy sequence of moves, some of which involve the entire assembly moving "upward" in the chassis. In my case, I saw that the mechanism moved in an entirely implausible way: The mechanism actually moved such that the innards ended up being higher than the top of the chassis. In fact, on its way it bumped into a part of the chassis and binded a bit before moving past toward the top of the movement. I got to thinking that if the top cover was in place the mechanism would strike the top and not have been able to move any further, constrained by the metal of the top cover. Indeed, there are witness marks on the top cover attesting to this interference. When bound like this I surmise the mechanism is unable to complete the move and faults -- perhaps it times out or hits a current limit on a stalled motor. Belts may also slip resulting in a loss of synchronization.

    With the top removed, the mechanism is (almost) free to move as it should which might explain why, when the top is off and I'm trying to see what's wrong, the thing seems to work.

    I then looked closer to see what could cause this. I appeared that the springs were not extended at all and that the flexible rubber mounts were basically near the limit of their flexibility toward the top. In short, the mechanism is being held up by the springs and "weak" rubber mounts whereas I think these mounts are supposed to be more "centered", allowing the mechanism to sit more in the center of the changer chassis. If this were the case the mechanism could move all the way to the top of its travel without hitting other metal.

    So I took the springs out and stretched them just a little bit to allow the mechanism to sag a bit in the chassis. I re-installed them, cleaned the laser pickup with a Q-tip and alcohol and put a wee bit of lube on the mechanism points I could reach. I put the top cover back on and tried it and it continued to load, play and eject from all 6 slots.

    So far so good. I've got it back into the radio and the radio slid back into the dash but haven't had the time to play with it much more yet and the weather's been soooo :poo:ty here I haven't driven the car yet so I don't know if this is "real" or just a fluke.

    It makes sense to me that the rubber mounts would soften up over time and allow the springs to pull the mechanism upwards and, further, that the mechanism would be insufficiently powerful enough to force it back down against the springs when the mechanism needed to move all the way to the top.

    Only time will tell I guess. Hopefully this isn't just a flakey works-for-a-day thing.

    I can pull it out and take some more pics showing what I'm getting at if anyone is interested. Might help to have a few intrepid souls try this on CD6s showing "CD error" to see if it's repeatable.
  2. Hmmm...good observation. My CD changer in my Expy has 7 discs in it when it locked up and showed only 5 then my wife inserted another. Might try this fix instead of removing it to get the discs and giving up on the disc changer.
  3. I made a video of the issue I was seeing with it:

    This was made a couple of days ago. Sorry for the crappy focus but it pretty clearly shows what I'm getting at.

    Basically, with the lid in place the mechanism will hit the top plate and will have to push against the force of the four suspension springs to push the mechanism chassis "down". I think this is too much force for the weak motor/drive to accomplish and it's leading to this fault.
  4. Here’s a photo-log of what I did to my MACH460 6-disc changer that has shown, for now at least, a measure of success in restoring function to the changer and staving off that annoying “CD ERROR” message.

    Note that this is not yet definitively proven to fix this problem. It will take time and perhaps others to try it to know whether I’m on the right track.

    This attempt was based on my findings outlined in a video I put on Youtube:

    After re-assembly the unit functioned as expected though I’ve only run it about 20 minutes or so.

    As well, this work requires fine tools and dexterity. Be aware that you are working with tiny parts, little springs, tiny screws and electronics and that it’s easy to lose or damage any of these things. Attempt anything you see here at your own risk.

    Tools Required
    • 7mm socket and nut driver
    • T-15 Torx screwdriver
    • selected small jeweler’s Philips (“star”) and flat screwdrivers
    • light grease
    • Q-tip or two
    • rubbing alcohol
    Removing the radio from the car
    • put the transmission in 2nd or 4th gear (manual) or move the selector to drive (auto)
    • lift the plastic trim up from around the shifter and move it back and out of the way
    • pull the trim off around the center console vents and radio by carefully pulling it away from the dash so the trim clips release.
    • unplug the connectors at the traction control, rear defog and fog-lights switches and set the trim aside
    • remove the two 7mm screws at the bottom of the radio

    • pull the radio out of the dash to expose the connections at the back and disconnect them

    • take the radio inside to a clean, well-lit work area
    Removing the changer from the radio
    • using a T-15 Torx screwdriver, remove the four (4) changer retaining screws, two on each side of the changer

    • there are two electrical connections made to the changer from the radio and they are made to the bottom side of the changer
    • the changer hooks or latches onto the radio chassis at the front

    • pivot the rear of the changer upward until you can access the two electrical connectors

    • the two-wire connector can be removed at the changer by grasping the connector body and pulling downward. The ribbon cable connects using a so-called “ZIF” (zero-insertion force) socket with a locking tab.
    • the tab can be unlocked by using your fingernail to pop the tabs “downward” on both sides. The cable will then easily slide out of the connector.
    • the changer can now be pivoted and pulled up and rearward to separate it from the radio
    Removing the changer top cover
    • there are six screws that hold the top cover to the changer chassis: remove them and set them aside (don’t lose them!)

    • lift the cover clear of the changer

    Modify the springs (and mounts if you dare)
    There are four springs suspending the mechanism in the chassis. I stretched these just a bit (see pic below) to allow the chassis to sag a bit lower in the chassis.

    I also removed the rubber mounts and turned them 180-degrees in their mounts. The thinking here is that if the mounts had softened in the “up” direction that by turning them 180-degrees I would then put the weak side facing “down”. Don’t do this if you’re unsure or lack the tiny screwdrivers.

    • here an image of a typical isolator mount (they’re all different but the idea is basically the same at each corner.

    • here is an isolator removed. The small screw holds a retainer ring in place.

    • I removed the ring and popped the rubber isolator out. I then turned it 180-degrees and put it back in the bracket and re-installed the isolator. You can also see here the degree of stretch I put in the four springs:

    • the dimple in the middle of each isolator receives a pin on the chassis. Getting these back in can be tricky but I found that a little spit works well :)

    • here’s the isolator and spring re-installed at that corner. The rest are similar. The second shot shows the modified spring:

    Grease is up and re-assemble
    Apply a thin smear of very light grease to the points indicated on the top cover using a Q-tip. There will still be contact and the grease will help prevent binding. Make sure you use a very light grease that doesn’t thicken into a useless solid when it gets cold!


    I also put a spritz of door-lock lube on a Q-tip and carefully touched it to the moving components I could easily reach. Don’t use too much; you don’t want the stuff contaminating the laser or your CDs. Just enough to help the mechanism out. Don’t forget that this mechanism is upwards of 13 years old now so the grease put in at the factory is likely dried out and/or displaced.

    If you’re brave you might use a Q-tip dipped in rubbing alcohol on the laser. Don’t attempt this if the laser is not easily accessible (spindle at the rear of the enclosure). If it’s not, just leave it be.

    Assembly is the reverse of disassembly.

    Quality Check
    Double check your work space. I had mine back the car and when I returned from testing it found this on the bench:


    I’m going to pretend I didn’t see that and see how it goes. I have no idea where in the changer that belongs so if something fails to work, I’ll have a basic idea where to start looking: Look for the two hooky-things with no spring between them.

    Use care when playing with these crazy-complicated things. There’s a zillion parts in there and it’s easy for some of them to come loose and get lost or forgotten when servicing them.

    Good luck!
  5. Added to FAQ tech
  6. I had this same problem a weekago, I didnt know there was a thread on this. I used electronics cleaner on all the gearing, then used wd40 with a needle and syringe to lube the moving parts, works like new
  7. Mine did this the day I drove it off the lot. Insert Tool cd (no pun intended). Good thing it was a burnt cd. My fix was
    1. remove cd player
    2. throw it away
    3. get another one and install it
    4. just listen MP3 player through audio jack