A good service manual with lots of info and a very fair price
Text excerpt from page 1 (click to view)
CD CHANGER SYSTEM
03 2003 49796
KD-SX841R CD changer control receiver
E ------- Continental Europe
CH-X550 CD changer
This model is combination of the CH-X550,CD Changer and the KD-SX841R. CD changer control receiver in one packing. Please refer to the service manual of CH-X550_E (No.49787)and KD-SX841R_E,EX(No.49790) for items other than this packing.