Hello Guys I have had a few cdx changers and the only time codes came up was when.......get this...I almost guarantee this is your problem.... You must be kinda wise and remember where things go and have a bit of electronics know how, just like how to put it back together, Dont be scared it is super easy!! IF THE CD CARTRIDGE WONT COME OUT OK Take the thing apart and you will see that the cds have escaped from their cage and now they are sandwiched in the units moving parts thus ERROR code! FIRST try to get them shoved into the cartridge they are supposed to be in! if you decide that is your problem but cant get anything to move just take it somewhere and dont pay too much it is just getting the cds out. In a good rearender accident I got into one time All my cds dumped out of the cartridge and into the unit. I bought a cdx-a20 on ebay "FOR PARTS" because it wouldnt work Well I just looked in the hole where the 10 cd cartridge goes in and long and behold John Micheal Montgomery greatest hits sandwitched in the mechanism ...I just reached in and pulled out the best country cd I OWN! I dint try the changer yet but I would guess it works better without the cd stuck in it! I REALLY HOPE THIS IS YOUR PROBLEM IF NOT SONY HAS SUPER CUSTOMER SUPPORT, I JUST TALKED TO THEM TODAY! SONY ELECTRONICS FT. MEYERS FLORIDA 1-800-222-7669