by Jeremy Schrag
In my last article, I showed you the main component in the audio system that came in the Dodge Stealth: the pre-amp, tuner, and cassette section. Today, we'll be tackling the CD player part of the system.
Also constructed for Chrysler by Mitsubishi, the CD player component of this system can be very problematic. Not only is it an early example of CD player technology, being built by Mitsubishi means that a multitude of bad solder joints can be expected on the inside. Additionally, the loading mechanism of this unit is belt driven. This means that should the belt ever break, the unit will no longer load or eject discs. Indeed, you may have a disc trapped inside the unit if the belt happened to break while the disc was in there.
I'm going to show you how to not only get into this unit, but also replace that belt. There is a strong possibility that the mechanism used in this unit was also employed in the Mitsubishi built Chrysler/Infinity single disc slave player, though I have never found one of them to examine the insides.
We'll start our journey by looking at the external panels. This is the bottom cover, where we find the sticker with all pertinent model information. This one bears the Mitsubishi part number "CD-209WY."
There are only four screws of note, and they all hold the bottom cover to the chassis. We'll be removing them later.
The back panel of the unit houses a single 8-pin DIN connector. The only electrical connection on the unit, this is where the interface cable to the main module plugs in.
We see five screws here in total: two silver ones which bolt the DIN connector to the chassis, and three bronze ones which clamp several parts to the chassis for heatsinking. For the purposes of this guide, we'll leave the bronze ones alone.
In the course of disassembling this component, several sizes of Phillips head screwdrivers are required. Most screws are either #1 or #2, but when it comes to the CD transport itself, sizes down to #000 are also needed. Fortunately, the smallest sizes are rare and you will not need to worry about those if you are just getting into the unit to fix CD read errors or clean the laser lens. To replace the loading belt, however, you will need Phillips head bits or jeweler's screwdrivers at sizes to #00 for certain.
Each side panel has two screws - these hold the top cover on.
We won't deal with the faceplate clips just yet. They are not accessible with the top cover on.
Finally, there is the top cover itself (not pictured). It is completely absent any remarkable features. Let's remove it now and look inside.
Once we get the cover off, we find that Mitsubishi has really crammed the housing full of parts.
We'll be removing the CD transport momentarily, so let's remove all screws indicated in blue. Then, grab hold of the tan colored tab attached to the red arrowed ribbon cable, and pull straight up to disconnect said ribbon cable. Take care not to pull the tab off the cable, or you won't get this cable to plug back in again.
We're going to remove the faceplate in a second, but first I want to show you this view of the left side panel with the cover off. Back in the early days, before CD players were calibrated via software, they had a big pile of analog potentiometers to adjust things like tracking and focus. Sometimes, you can use these controls to make the unit play discs they otherwise cannot, like rare 99 minute CD recordables, or CD recordables in general.
My strong recommendation is that if you do try to do this, mark the positions of all controls before you get started. Do not adjust them if the unit cannot read any discs at all... it is more likely the laser power adjustment needs to be touched up instead to compensate for an aging laser, and that control is not found here.
It is also important to remember that only the tracking offset, tracking gain, focus offset, and focus gain should be adjusted. The others require access to a service manual and test equipment. Samuel M. Goldwasser has published an excellent article on how to adjust these controls here. You may be wondering which controls of the seven seen above are the ones I speak of:
It is unlikely that you will need to do anything with the second tracking offset adjustment. The functions of these adjustments are fairly intuitive... tracking gain controls how far the laser sled moves before it tries to read the disc, while tracking offset affects the spacing between tracks. Adjust these controls if your disc is skipping forward in time. Focus offset and gain affect the ability of the laser to focus... these adjustments are helpful if the disc is skipping in place or cannot be read at all, despite modifications to the laser power setting. Note that if the laser itself is burnt out, no adjustment will help.
Now, we'll release the clips on either side, and on the bottom, and pull the faceplate off. We cannot remove the circuit board yet - nearly the entire deck needs to come apart to do that. In the meantime, red arrows indicate the screws that hold the board on.
There are two lamps that illuminate the buttons, and a further two that light up the LCD display. We'll address those later.
For now, let's gently remove the CD transport and fold it over like so. We now have two more ribbon cables to disconnect, and they work the same way as the one we have already unplugged. I've indicated them in red.
This is where we find our laser power adjustment: right on the laser sled itself (red arrow). It is important to adjust this control in minute increments or decrements, and then test each adjustment, if the unit is not playing discs. If you are tweaking to get it to read CD-Rs better, make sure you test both the recordable and a standard CD to see if both play. It is equally important to adjust this control without power applied to the laser, but given the way this unit was constructed we don't need to worry about that. It is impossible to power the transport and still adjust the control, because the control cannot be accessed at all with all three ribbon cables to the mainboard attached.
A 3mm 12 volt grain of wheat bulb is employed by the transport to light up the CD loading slot. If you wish to replace it, here's a look at the relevant area of the transport.
The lamp is housed in a special yellow filter sock that fits over a peg. De-solder the wires that supply it (indicated in blue), slip the filter sock off the peg, and just work the wires out of the mechanism. You may find it helpful to bend that tab seen in the middle of the picture holding the wires in place downward to make things a bit easier.
Now, we're going to get to the bigger job - replacing the loading belt. But before we do, we need to de-solder the wires that supply the loading motor. I've indicated them in red. Note that they are labeled as to which wire goes where. Just touch the iron to the solder joints and pull the wires out.
While you're at it, take some contact cleaner and shoot some into those switches arrowed in blue. These tell the circuitry what the mechanism is doing, and if they are dirty it may result in strange behavior while loading discs.
Before we remove the loading motor assembly, pay special attention to the green arrowed loading arm. This must go back in exactly as shown in the picture, with the upper slot in the pin you see there and the tab on the far left pressing down on the corresponding tab in the transport. You do not need to remove any of these e-clips, fortunately... it is possible to remove and install the assembly without bothering with those.
Also, note the position of the wires to the loading motor, arrowed in blue. You will want to route these the same way you found them.
Now... take your Phillips #0 and a pair of pliers and latch on to the metal near the red arrowed screw in the middle. You will need to press hard to break the threadlocker on that screw, and if you don't hold onto the metal with pliers the metal will bend. You don't want that. Remove the other red arrowed screw, then gently turn the transport over.
Un-stick the ribbon cable seen here and gently push it to the side for access. Now, you can maneuver the loading motor assembly out of the transport.
Access to the belt is prevented by a worm gear, a platform, and three Phillips #00 screws. Placing a thumb over the e-clip on the end of the worm gear (red), pry it off the shaft with a tiny slotted screwdriver or dental pick. These tend to go flying into dark corners unless you stop them, thus my advice to use the thumb. Note that there will be a graphite washer directly behind the e-clip... do not lose that washer. It helps the worm gear move smoothly, and keeps it from wearing down on the e-clip. Now, pull the worm gear off the shaft.
Now, you can remove the three screws (blue) holding the worm gear platform to the motor bracket, and remove the platform. The belt can now be replaced. I measured the belt at a width of 1mm, and an internal circumference of 38mm. You will want to use a replacement slightly smaller in internal circumference to compensate for belt stretch. The belt in this particular unit is hard with age and ready to break.
Once the belt is replaced, re-assemble and reinstall the loading motor. Bring lots of patience when it comes time to put that little loading arm back into position. It will go without too much fuss, but it may take a few attempts.
Now that we've dealt with that troublesome little belt, let's get even further into the deck. We'll remove the power and interface module next.
Disconnect all cables arrowed in red, then de-solder the ground wire arrowed in blue. On the right side panel, you will find two screws - remove them. Next, remove the two screws holding on the 8-pin DIN connector on the back.
Pull the whole shebang straight up and out.
This being a Mitsubishi built unit, start looking for bad solder joints on the underside of the board. I found several on this one. Note that if the fuse has blown, you're looking for a 20mm long 3 ampere fast blow replacement.
Next, a look at the bottom of the mainboard. This requires removal of the bottom cover, of course. My example had numerous bad solder joints on this board as well.
It is possible to remove the mainboard via the de-soldering and untwisting of several metal tabs, as well as removal of the three bronze screws on the back panel, but we won't go that far today.
What we will do, however, is remove the faceplate circuit board at long last. This step will also try your patience, as the ribbon cable to that board is soldered in place (red arrow). I used a solder sucker to remove excess solder from each pad first, and then was able to remove the cable by applying gentle pressure as I touched the iron to any stubborn joints. To re-solder these joints, a somewhat special technique was used in that I applied the iron to the cable first, added my fresh solder, and then pulled the solder downwards onto the circuit board trace. It is best to use a low powered iron for this, and do the pulling action quickly and confidently. If you do it slowly, you risk damaging the cable or the circuit board from excess heat.
Now that the faceplate board has been removed, we can look at the illumination a little better. There is a special filter sock over the left side lamp in this picture... this is because the lamp used is not the standard 3mm grain of wheat style. Really, I have no idea where to begin looking for a proper replacement for it. You will likely just have to use the grain of wheat style, and live with the reduced brightness.
The back of the board shows us where the lamps illuminating the LCD display go. All lamps are in twist lock bases - use a flat bladed or clutch style screwdriver to remove them.
In the inset, I've shown you the two types of 12V lamps used with the oddball big boy in the center and its special filter on the right. If you're feeling adventurous, you can now change the illumination of any part of the front panel to any color you can find a filter sock for. eBay is a good source for both the socks and the lamps.
This concludes my look at the Dodge Stealth CD player. As mentioned, there is a better than good chance that many features of this article apply to the Infinity single CD slave unit as well. It may even be possible to interface this CD player with a traditional Chrysler/Infinity I, II, or III unit, but I do not have the means to test that theory at this time. Do so at your own risk.
At this point, the only thing left to do is put it all back together. Good luck.
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