Repairing this Sanjin DX-400 "MagicChanger 400 Disc" was an interesting but long winded diagnosis and repair. I ignored my initial thoughts of checking the power supplies in favour of diving into the mechanism fault which made the repair a bit longer than necessary. Total repair time 4.5 Hours. I've therefore cut a lot from the video. Enjoy. The unit is also known as an ACESONIC DGX-400 - 400 Disc DVD CD G Karaoke Changer. And also as a SONY CDP-CX400 / CX450