OLAH Kam. As User's Manual indicates on section Error Messages you Should contact with your Pioneer DJ store (where you buy your CDJ-350 unit)
Follow this link
But try to update your drivers & Firmware before
http://www.pioneerdj.com/es-es/support/software/cdj-350/
Find an authorized store near you
http://www.pioneerdj.com/en/shops/
Take care