Cadillac Seville / Cadillac Eldorado Forum Discussion, 12 disc cd changer diagnosis. in Past Cadillac Vehicle Discussion; i asked this morning and was directed to some great threads so big thanks to all the ppl who posted. ...
i asked this morning and was directed to some great threads so big thanks to all the ppl who posted. learned how to pretty much break the whole thing down, which is what i did all day. i can tell you what i did, what it does and doesnt do. if someone could diagnos the symtoms for me it would be greatly appriciated. i already diagnosed that it still isnt working, lol.
what i did:
disassembled itdown to where the entire black case was removed. front panel with cartrige door only attached by the wires and connectors. same with the back, even seperated the sisterboard i belive they called it and just plugged it in and held it as nessasary.
i start with the mechanical parts, first watching what it did when powered by the car then unplugged it and proceed to manually move it through its desined process.
all the springs, gears, stop and reverse points were there and none broken. and would manually cycle through.
when plugged in it would start the initializing process if the player side (not the cartridge side) was anywhere except the top. but it would only start, raise it to the top and stop. pushing the little button of the front would get it to try engage in the lowering but imediately stopped. all ended in the same no source loaded message.
the above lets me know its not cycling trays. so i wanted to see if it would play a cd if it was loaded. before i gently cleaned the laser with alcohol. then i manually loaded a cd and tried powering it on every combination i could thing of,. ie plugged in before, after, amd in between but never detected or played the disc.
the inserting and ejecting of the cartridge worked fine.
so with my 8hrs of experince behind me i am lead to believe it is something in the card, board, electriak side of it. all appeared in good physicall shape but i have no idea how i would dettermine which one is the problem assuming im assuming corectly.
if someone knows or needs a more specifc answere about what u saw ir didnt see please ask, and thank you for helping.
The firmware in the CD changer is programmed to read all disks (cycles tray by tray) and actually remembers what tray has a disk and how many tracks. This memory is reset in the moment the cartridge is ejected.
Unless the mechanism is able to cycle trough all 12 disks it won't allow any disk.
Check that stair looking mechanism in the back of the unit, that is the guide for the trays, that usually bends, is suppose to move very easy.
Also you don't need to have the disk changer in the car to test it, you can do a bench test as long as you have a 12V DC power supply capable to supply at least 1A. The power supply pins are 5 (12 V DC) and 7 (GND). The case of the unit is connected to GND so all you need to do is ground the case and apply the positive terminal to pin 5.
Now assuming the unit does cycles trough all 12 trays when the cartridge is inserted, as it cycles each disk observe if the motor is spinning the disks and while the disk is spun observe the movement of the lens guide (also the lens has a small amount of adjustment in that guide).
If all that is working then you have most likely issues with the lens (not reading disks). That could be because of the lens or the mechanics are out of alignment.
If the motor is not spinning the disk or the lens is not moving on the guide (there is that screw/worm screw motor) then look at the banner cable that provides power to the 2 motors. Very common issue with these changers is corrosion in the banner cable connector on the PCB above the cartridge due to water intrusion. The fix is simple, just disconnect the cable (standard banner connector release mechanism with that plastic shim) and reconnect.
outstanding sir that was the kind of info i was hoping for. you can only learn so much looking if you dont know what your looking for. i believe my grandfatha told me that, lol. should go smoother tomorrow. and just to clarify, even though i put a cd in the "play" position and it didnt spin doesnt mean it wouldnt have spun if it would have cycled all 12 tray? thanks again
SHOULD cycle all 12 trays (even if missing) first thing after inserting the cartridge.
During each cycle the disk should spin for ~2 sec and the lens should move across (not all the way just partially).
This should take about 45+ seconds (for all 12 trays).
Again, best thing is to do this inside on a flat surface using a 12V DC power supply.