The menu / hold button could be engaged, see button 14:
Controls at a Glance
1. Neckstrap Insert
2. USB Port
—. Connect to a computer to transfer media files to
3. 3.5mm Headphone Jack
4. Menu Navigation: Up
5. Menu Navigation: Down
8. LCD Touchscreen
—. Tap the display with your finger to activate the
9. OK Button
10. Reset Button
11. miniSD Card Slot
—. Load a miniSD memory card here to upgrade
the memory capacity of the player.
Page 6 Coby Electronics Corporation English Right View
12. Power Button
—. Press and hold to power the player on/off.
13. Volume Button
14. Menu/Hold Button
—. Press and hold to disable the player controls.
Press again to re-enable.
See also page 8 and 9 of the Quick Setup guide for the MP822: