I have a sony cdp cx400 that will turn on but will not turn off. When i first turn it on it says no disc, i push the open door button nothing happens push power and display shows sony cdp cx400.

SOURCE: CD player door won't open

try to dismantle the unit and check the rubber belt on the motor

SOURCE: player reads no disc

make sure you are putting them in correctly

SOURCE: Putting a new door on my Sony CDP CX300

u must remove the broken old door carefully by removing the rubber belt which is connected to the dc motor and bear by there be a white colour plastic which holds the door u must remove that and then u must put replacement & once again u must connect those all properly so it s difficult... just visit technician....

SOURCE: Sony CDP-CX300 CD won't play

The rubber drive belt for the c/d load mech is streched or broken,
replace the belts there is another that drives something else so change them both while you have it open

SOURCE: ALL SEEMS FINE BUT WON'T PLAY DISCS.

I would suggest taking a can of compressed air to the disk tray to ensure the laser is clear of all possible debris

Testimonial: "UPON REMOVING THE COVER TO DO AS YOU SUGGESTED, I DISCOVERED A BELT WAS OFF T0 THE DISC LOADER. THANK YOU"