Sony CDX-M800 CD Player - Answered Questions & Fixed issues

The wiring diagram is on the second page of this installation manual.

You must have the wrong PIN
To check
The radio SERIAL NUMBER is required for a code
First remove the radio from the dashboard.
Then post the radio make+model plus all the letters+numbers on any labels,barcodes or stamped in the metal casing.
This information can then be used to see if a code can be calculated

You can enter a 4-digit security code as an option after purchase of the unit. If you do so, make sure it is noted down somewhere. If you did select a code (or the previous owner has done so) this must be used when the unit is removed from the vehicle, or the constant power source is disconnected from the unit. When constant power is restored to the unit, the security code must be entered before the unit becomes operational. If the code is lost or forgotten I am afraid the unit has to be re-coded by a Sony dealer.
Hope this helps, Good luck with it.

Hello,

You will need to get the papers that came with your car, search all the documents that came with the car, the code to reset your car radio is written on one of the documents that came with your car. If you cannot get it, you will need to get the serial number on your radio and contact the dealer for the reset code, because, the dealers have the reset code, but you will need to tender prove of ownership before this can be done.

Can you provide me the serial number of your car radio,maybe i can suggest a code that may work.

Take care.

Radio code is specific for each and every car. It is specific like anti theft code.

You can get it by providing your VIN# and registration details in authorised dealership. Nobody else can provide you. If anybody can provide you that , then there is no meaning of security for your car..

Remove the radio from the dashboard

Then post all the letters+numbers on any labels or stamped in the metal casing

Also quote the make of car

did you push the wires through the back of the fuse pannel when you changed the fuse

sony cd players do not have codes.

you more than likely have a bad flexible cable(s).

here is the manual. just download.

http://audio.manualsonline.com/manuals/mfg/sony/cdxm800_1.html

The ribbon cable is a VERY common problem on these units. Mine went out and I picked up a replacement cable on ebay for under $20. If you are at all mechanically inclined, you can replace it yourself fairly easily. It is a little scary to look at your stereo in a bunch of pieces on the table, but is really an easy fix. Take the flip-face off of the main unit and you will see the ribbon that connects it to the main box. You will need to take the face place apart (it comes into 3 pieces, the front back and middle). When you see where the ribbon connects inside the face, pull back the little clips on the side and slide that end of the cable out. Mine did not look broken, but replacing it fixed the problem. Take the top off of the main unit, and unscrew the disk drive. Once unscrewed it will lift right out (it is plugged in on the bottom so just pull straight up until it comes free). Once you have that out of the way you will see the ribbon. This end is a little trickier. It is wound around a little spring that lets it in and out as the face moves. Look carefully at how it winds through the spring - you will need to put the new one in the same way. (it may help to take a pic of it to reference when you put the new one in) Unclip this end of the ribbon like you did the first. The new one needs to go into the main unit first. Install this the same way you removed the old one, around the spring, and through the slot that will connect it to the faceplate. Connect the other end to the face, then put the face back together and reconnect it to the unit. Replace the disk drive and the top of the unit, and you are done. Its pretty self explanitory when you are doing it, just take it apart till you see the ribbon, then put it back together the way it came apart. It's fairly easy, but be honest with yourself. If you are not good at mechanical issues, have someone help you. Good luck!

The head unit will drive four speakers, 2 front ,2 rear.
Best way to add two more speakers and a sub is to get a 4 channel amp. Hook it up to the RCA jacks from your head unit. Bridge two channels of the amp to drive your sub, and use the other two channels of the amp to drive the extra two speakers. Just make sure whatever amp you get it's bridgeable.

pleace send pin code cdxm800 sony

If it is the security code you are looking for, try these solutions. See how you get on. Solutions that have been tagged as workers... try the soft fix first, then if your game,the 4 blob trick... dunno bout that one??
http://www.fixya.com/support/t225385-sony_cdx_m800_code


 I recall changing out the 8 pin eeprom chip where the security code was stored on Sony and Pioneer Head units where customers had forgotten their code when the units were brought in for service, so  you start with a fresh code. That was a few years back but:).  
Will have an 8 pin dip chip as detailed in this post if thats the case for this unit. You may need to supply your Identification toSony to order the part. This is how it used to be,and it may be doable only at a sony agent, this being a security part for the unit. Let me know howyouget on. 
regards robotek . 

I think you are going to need the service manual to properly troubleshoot this. You can try to follow these instructions without one, but having one makes it so much easier. You will need to have the radio on a work bench with the CD mech out and the harness out of the car as well so you can turn on the radio and check some voltages. Since you are an electronics engineer, I should not need to point out any safety precautions, after all, I am just a technician.

For starters, check the voltages at pins 7,8,15,16,17 on connector CNP909 the 24 pin connector for the display on the main board. Pin 1 should be the one closest to the corner of the board that connector is near. Pins 7 and 8 should have 10 volts each, pin 15 should have 5 volts and 16 and 17 should both have a much higher voltage. I suspect you may be missing the 10 volts from pins 7 and 8. If so, check the voltage at the emitter of Q914 on the main board. It is a digital transistor (surface mounted) and when the power is on it should have 10 volts there and 10 volts on the collector and zero volts on the base. If any of those voltages are not there, check Q915. It should have 10 volts on the collector, 5 volts on the emitter and 5.6 volts on the base. It is not a digital transistor but is surface mounted and much bigger than Q914. If you are missing the 5.6 volts on the base, check the zener diode D905. It should have 5.6 volts on the cathode and ground on the anode. The cathode goes directly to the base of Q915. Use your multimeter on the diode check mode and see if it looks normal. Could be that zener diode is shorted. There is also 2 capacitors in parallel with that zener, C928 and C930, check those as well. If one of them shorts out it will look like the zener is shorted.

You can also check CNP805 for the 10 volts, it is supposed to be there as well. I don't know what pin number but I think that connector is on the top of the board. The 10 volts should be either pin 5 or pin 7, depending on which side you start at. CNP805 is the connector for the sub-board with the reset switch on it. After you know what these voltages are on CNP909 we should be able to narrow down the problem.

I hope this helps, I really do not have a lot of time right now. I have a power supply to fix and a big stack of car amplifiers to repair. Let me know if you need more help, I just may not be able to answer as quick as you may like, but I will answer when I have time.

Dave

you can buy these from ebay just type in sony cdx m800 ribbon theres loads on there pretty cheap aswell hope this helps

hello mate yes i have a rapair manual please give me your email

this is a coincedence. The CDX-M800 had a HUGE problem with the ribbon cable on the face going bad, causing this exact problem.
$14.00 and some time will put it back into perfect condition.
http://cgi.ebay.com/ebaymotors/Fix-your-Sony-CDX-M800-flexible-ribbon-cable-CDX-M800_W0QQcmdZViewItemQQ_trksidZp1638Q2em118Q2el1247QQcategoryZ43947QQihZ020QQitemZ300287945333QQrdZ1QQsspagenameZWD1V#ht_2258wt_1213

If you are talking about hooking the truck to an engine diagnostics computer that will not likely diagnose the problem. The dealer wil have to troubleshoot the wiring and that can get expensive if the tech is not super proficient in that area.

Have you had ANY non factory modifications added such as alarms, remote starts, aftermarket lights, or trailer wiring connections? If so I would start there. you may email me with more details at [email protected] or visit www.brianbell.net. Please elaborate and I will do what I can to help you.

JUST PRESS THE RESET BUTTON
IF THIS DOSNT WORK CHECK THAT THE PLUG WIRES ARE SECURE I HAD THIS PROBLEM LAST YEAR AND IT TURNED OUT THAT ID UNPLUGGED THE STEREO BUT AS I RECONNECTED IT THE PIN HAD PUSHED THE CONNECTOR AWAY SO SOMETIMES IT WORKED OTHER TIMES IT DIDNT WHEN I HIT A BUMP IT WOULD MAKE THE CONNECTION BREAK