Marantz SR7009 Owner's Manual page 276

Contents Connections
Setup Lock
Protect settings from inadvertent changes.
o Lock
On: Turn protection on.
Off
Turn protection off.
(Default):
When cancelling the setting, set "Lock" to "Off".
NOTE
When "Lock" is set to "On", no setting items are displayed except for "Setup
Lock".
Front panel Display
Playback Settings
Rear panel 276
Tips
Remote Index
Appendix