Marantz SR6009 - Manual (Page 214)

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