by Jeremy Schrag
In this guide, I plan to show you how to attack the Mitsubishi made Chrysler CD/cassette combination player to both increase CDR compatibility, and also repair the most common problems with these.
Before I get started, it should be mentioned that not all of these are created the same – some of them are put together differently. While these are modular, with CD or tuner modules that will interchange with other similar models to some degree, I cannot promise full compatibility.
In this post, I'm going to deal exclusively with the older style combo decks, which seems to include the majority of them. I don't have one of the newer ones here to show you the difference in construction, but those newer ones don't suffer as badly from CD alignment issues or the other problems these often face.
Above, we see my parts deck in all its dead splendor. I can't show you the repair it would take to bring this one back to life, yours truly killed the power supply, but it'll do for this guide. To begin, remove the fader knob, EQ knobs, and volume knob by pulling them straight off. Then, remove the four screws on the sides of the faceplate and pull off the faceplate. There are two screws holding on the top cover – if you plan on working on the CD module, you might as well remove those now.
You should now be seeing something like the above picture. With the faceplate off, we can now repair two of the more common complaints with these – a volume control that won't control properly, and buttons that either take too many presses to register or give you the wrong functions. It should be noted that other Chrysler decks get these problems too, most commonly the CD changer control cassette deck (the one with the mode button).
We'll start with the volume control. Over time, the contacts in these tend to get dirty. However, we can't just shoot them with contact cleaner – they're too well sealed to let us off easy. Instead, we have to do this to them:
As you can see in the above picture, there are four sets of metal tabs holding the volume pot together. Normally, they are spread apart in a Y shape – using a small screwdriver, you need to carefully bend the arms of the Y straight, and then you can remove the top part of the volume pot. Now, it's easy to clean the contacts, what with them being in plain view now. Once you've done so, put the volume pot back together the way it came off, and bend the tabs back into the Y shape. Give the pot a few twirls to make sure the cleaner has a chance to work. While you're at it, refer to the below picture and shoot cleaner into the green pots on the side of the fader control.
On to the buttons. In this picture, we can see the buttons are actually membrane switches that go together in three pieces. These are notorious for getting dirty on the early combo decks – I've had two of the early ones so far, and both needed work here. As you can see, there are little metal clips holding these together. To clean the button contacts, first remove those clips (watch that they don't fly off somewhere). Then, pull out the button plunger. Now, you should be able to see the membrane contact itself – it will be a green dome shaped affair. Very gently, remove the membrane with tweezers. Now, you should be able to look down into the button housing and see the two contacts. Don't use contact cleaner here – it won't work for very long. A pencil eraser works best I find. I usually cut several small squares, slip them onto the end of a jeweler's screwdriver, insert them into the button housing, and then spin them over the contacts; replacing them with new eraser segments as they get dirty. This works extremely well, I find. My CD changer control deck (has the same membrane switches) didn't have one working button when I got it – now they all work thanks to the eraser trick.
My usual approach is to take all the buttons apart and clean them all before reassembly – that way you don't lose track of which buttons you've done, and won't have to get back in there anytime soon. Putting the buttons back together is easy enough – just replace the green membrane with the black contact facing down (dome side up), put the plunger back in, and replace the clip.
On to the fun part – tweaking and repairing the CD module. This procedure should also help with those decks that spit out error messages when trying to read CD's, or won't play them when it's too warm or too cold.
Before getting into the tweak, cleaning of the laser lens should be tried. This should be possible with only the top cover removed and the module still in place… you can usually get a Q-Tip moistened with isopropyl alcohol into the CD section past the mechanism toward the back to the laser lens itself. If you can't get at the lens this way, the whole module has to come out and apart.
Disassembly is where the old and new combo decks differ. On the old models, the CD module is held in with screws. On the new models, they used screws and clips. The old models require removal of the faceplate circuit board to remove the CD module, while the new ones don't.
Since we're working on the old models, I refer you to this picture:
See the orange arrows? These are pointing to three metal tabs that are holding on the faceplate PCB. Take a good pair of long nose pliers, and twist them to release the faceplate PCB. The circuit board will be attached to the rest of the deck by a small ribbon cable – no need to remove it. We won't be spending much time here. [b]If you see[/b] screws holding the PCB on instead of metal tabs, you have a newer combo deck and this guide won't apply to it.
Remove the screws indicated by the arrows in the above picture. You need a Phillips #1 driver for this, and make sure it has a good grip on it – these screws are on there tight. I usually just take these out for good – gravity and friction do a good enough job of holding the CD module down. I've even sold one of the decks I permanently removed these screws from – no complaints from the new owner. Just leave them out, put the faceplate PCB back on, twist lock the three metal tabs, and put the faceplate back on. You can even screw the faceplate on now.
At this point, there is now only one screw on top holding in the CD module at the back of the deck by the connectors. Remove it. Then, very carefully lift the module upwards – I use a small screwdriver at the front to assist in removal. Turning it upside down may also help, but be very careful not to let the module come out too far just yet. There will be a ribbon cable linking the module to the deck's mainboard below it.
Now, we have two options – tweak it with the ribbon cable still attached, or remove the ribbon cable as necessary. A word of caution – that cable doesn't like being plugged in too many times, and you could lose the blue stiffening piece that holds the cable in the connector. When that happens, it becomes infinitely harder to plug the cable back in, as you have to make sure all the wires are straight when plugging it in, and then slide the blue strip back in to secure it. Even for me, who had to do that on this very deck, this is hard. But, if you're gentle when plugging or unplugging the ribbon cable, it should hold up fine. You can unplug it either at the module itself or the mainboard – I found the mainboard connection easier to use.
Fun fact – you could put the deck together now without the CD module and the tuner and tape sections would still work. You'd just have no CD player.
Before continuing, look at the front of the CD module – there may be several pots accessible from there. Don't adjust these, or it may never play a CD again. There are adjustments here that will allow the player to track a 99 minute CDR, but I won't go into that here. For one thing, those CDR's are hard to find. For another thing, the player still likely won't seek to all the tracks on those, and probably won't play most of these discs all the way to the end. I have the best luck on those burning at 8x or slower.
We're almost ready for tweaking. Set the module on its side like this, CD slot facing to the right. This puts the laser sled in the best position for the tweak. Then, remove the two top screws holding on the CD module's PCB, and loosen the two bottom ones. This should allow you enough access to the laser power pot on the CD sled.
As I mentioned with the Infinity IV tweak, make note of the exact position of the pot. Use a marker to mark the setting if you can. These combo decks are really picky about this adjustment – a sixteenth of a turn too far, and it won't read anything.
If the deck currently won't read any CD's: first try tweaking in a tiny increment clockwise, a sixteenth turn should do it. Then, proceed to the testing phase. If it still won't read anything, set the pot back to its original setting and try a counter-clockwise tweak. If that doesn't work, back to default setting, and a slightly larger clockwise tweak.
If the deck will read normal CD's but not light dye CDR's: proceed as above, clockwise. It should now be reading both media… try various examples of both before assembling the deck again. This should also fix cold or warm error issues.
If the deck reads normal CD's, light dye CDR's, but errors on the dark dye ones: fuhgeddaboudit – there's no tweak you can do to this deck to get them to read everything. You can adjust them to read dark dye CDR's, but more often than not they now won't read anything but. The newer decks are more tolerant of CDR media though.
There are a couple of ways to test these between tweaks, the time saving but slightly risky way, or the long but less risky way. I use the time saver myself – to do this, you do the tweak, screw down the four screws for the CD module PCB, reconnect the ribbon cable, place a wooden board on top of the deck, and the CD module on top of the board. You can then safely apply power to the deck and use it without worrying about letting the magic smoke out. Be very careful though – one slip that allows the CD module PCB to touch anything metal in the deck below can very easily blow the deck, the module, or both. I found that out the hard way when I tried to do the time saver with the deck still in the car. The long way is to slip the CD module back into the deck for testing without screwing it down.
If you're leaving out those front screws like me, once the CD module is working to your satisfaction you can now set it back into the deck, replace that one screw by the connectors, reinstall the top cover, and enjoy.
To close, I thought you'd all like to hear where the various modules are located in these decks. I'm marking with an asterisk where I've found one can swap modules with other similar decks.
-tape module: bottom of the deck, underneath the mainboard
-tuner module*: right side
-preamp module: bottom of the deck, between the back cover and tape module
-power supply: left side, bottom of the deck
-power amp module*: left side, top of the deck above the mainboard and power supply
-CD module*: right under the top cover
The rest may be swappable too, but I haven't tried it.
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