See also:

CD player operation
NOTE - Make sure to always insert a disc with the label side up. If a disc is inserted with the label side down, the player displays “CHECK DISC”. Refer to “When the following messages are ...

When “CHECK DISC” is displayed
Press the eject button to unload the discs. Check that the disc is not damaged or scratched, and also check that the disc is inserted correctly. This message may appear when using some CD-RW discs ...

MUTE button (if equipped)
Press this button if you wish to immediately cut the volume to zero. The audio display will show “MUTE”. If you press the button again, the original sound volume will return and “MUTE” turns off. ...