A Sony CDX-MP450X Whose Face Unit Won't Respond And Much More

Hi everybody-

Well, this is a problem that started around the beginning of Feb. 06. I have the afformentioned head unit (whose full name is CDX-MP450X) installed in my '93 Camry LE IL4. All of a sudden, the face plate stopped responding to commands, with the exception of the off button. Now, I can put a CD in, even an MP3 CD, and it'll play just fine. It still displays CD Text and MP3 file names but, as I said, the face unit doesn't respond. When I pull it down and put it back up, it says "No Data".

So far, I've tried using isopropyl alcohol to clean the contacts between the faceplate and unit many, many times (with it working initially for about 30 secs and then being nonresponsive and now that doesn't make any difference), doing a reset many, many times, and even took a look in the faceplate itself to check if there was a short (which there wasn't). I've had the unit since the end of '01 and this is the first time I've had issues with it. Now, I've probably messed things up even more by using a screwdriver to touch the contacts on the unit to adjust various things, which of course the manual says not to (but I hadn't read that far in).

My question that I pose to you all is if there is anything that can be done to salvage the unit. I'm a poor college student, and really can't afford a new head-unit (the original was a graduation present). I talked to Sony, which was a total waste of time, and in the end, the only thing they could recommend was to take the unit out and do a hard reset (which I haven't done because it's a pain in the ass and I doubt it will make a difference). The other idea I had was to replace the contacts on the unit itself, but I'm not exactly sure where to get a replacement for that part and if it's even possible to replace.

On a separate, but somewhat similar note, the sound sometimes cuts out to the speakers, with the head unit not shutting off. The only way to fix this is to knee the drivers side door. I'm thinking that it's probably a frayed wire or some such thing (probably within the black plastic sheath that is on the inner hinge of the door), but I don't want to have to take the freaking door panel off (just getting the freaking door handle off is a huge pain). I am going to have to anyway, as the lift mechanism for that window is shot and is in need of replacement and the master switch has been giving me issues as well (fuse continually blowing out) but I don't want to have to disassemble and reassemble it twice if I don't have to.

Another aspect of this story is that my roommate, who forgot that once you put the drivers side window down, it ain't going back up again, which happened while I was away and, as a result, the drivers side of the car got rained upon (this was during Jan. in WA state). This leads me to believe there might be a moisture issue, but, excepting the head unit funkiness, the other problems predated this incident (although I've done much the same thing, but didn't roll down the window all the way). There seems to be a general screwiness to the electrical system of the car in general (most notably the "door open" setting on the dome light working only some of the time). Mechanically, the car is in fine shape. It's just the electrical system that's been giving me grief.

I already have the repair manual for the 92-96's, so I know what does what, and I have a multimeter so I can do all kinds of checking of resistance and such. What I don't have is a lot of experience working on electronics (at least on a physical level).

So, if anyone has any insight into any or all of the previously listed problem, a response would be extremely appreciated. Thanks for reading this long and rambling post.

- Ben

Ok first for the head unit, you've had it since '01 for being a sony that's an extremely looooong lifetime recommend a replacement such as higher end pioneer premier (very reliable for reasonable price) or good alpine (extremely reliable and long lasting but expensive. About the speakers do all the speakers cut out in the car or just the driver side door speaker? If all of them cut out then there would be nothing in the driverside door that would cause all of them to cut out only that one. You didn't mention if you had already replaced the door speakers but if not I suggest looking at local pawn shops to see what you can find that fits your car. As far as the dome light not working when you open the door that's probably the door jam switch which is usually pretty easy to replace on most cars and not very expensive.

Dave-

Yeah, that is a long time for a Sony unit to last (didn't know shit about car audio at the time and was one of the only MP3 decks out there). I took the unit out and somewhat apart today, and it looks as if all I really need to replace is the relay board (which I totally messed up by being a little too rough and ungluing the ribbon cable that connects it to the actual unit, thereby making it totally inoperable). Any ideas where to find one?

As for the speakers, all of them cut out. When it transitions from the speakers not working to them working again, I hear a popping noise. As for new head units (and that's what it looks like is going to be nec.), do you have any recommendations for a sub-$150 unit? The only feature I'm really looking for is the ability to play MP3 cds (and if possible, to have an 1/8" aux input on the front). I'm also apt to sell the car within the next year or two, as I'm probably attending a grad school in NYC, so longevity isn't of the utmost importance (at least for me).

Also, the dome light problem happens with all the doors. Is it possible that all of the door jam switches have died or are dying?

Thanks for the response.

- Ben

For a replacement head unit go to electronic express and check out the pioneer cd players they have. I have the DEH-P680MP which has the AUX jack that you're talking about and is also IPod ready as well. The one I got I paid about 230 for and with past experience with Pioneer they will last as long as the sony you have now if not longer if taken care of. The speakers going in and out like that could be another result of the head unit you have now starting to crap out on you. As for the dome light, so the light will not work with any of the doors opening up? If that's the case then I'd first check to see if they might have put a fuse in for the light if not then I would start at the light and work my way backwards from there as it's possible but very unlikely that all the switches would go out. Also try unplugging all the switches and plugging them in one at a time to see if one of them might be shorted out causing the rest to be bypassed.