Locking control keys
With the control keys on the projector locked, you can prevent your projector settings from being changed accidentally (by children, for example). When the Panel Key Lock is on, no
control keys on the projector will operate except 
Power.
1.Press 
/ 
on the projector or remote control or
go to the SYSTEM SETUP: Basic > Panel Key Lock
menu, and select On by pressing 
/ 
on the projector or remote control. A confirmation message displays.
2. Highlight Yes and press MODE/ENTER to confirm.
To release panel key lock, press and hold 
/ 
on the remote control or projector for 3 seconds.
You can also use the remote control to enter the SYSTEM SETUP: Basic > Panel Key Lock menu and press 
/ 
to select Off.
• Keys on the remote control are still active when panel key lock is enabled.
•If you press 
Power to turn off the projector without disabling panel key lock, the projector will still be in locked status the next time it is turned on.
Operating in a high altitude environment
We recommend you use the High Altitude Mode when your environment is between 1500 m
Do not use the High Altitude Mode if your altitude is between 0 m and 1500 m and ambient temperature is between 0°C and 35°C. The projector will be over cooled, if you turn the mode on under such a condition.
To activate the High Altitude Mode:
1.Press MENU/EXIT and then press 
/ 
until the SYSTEM SETUP: Advanced menu is highlighted.
2.Press 
to highlight High Altitude Mode and press 
/ 
select On. A confirmation message displays.
3.Highlight Yes and press MODE/ENTER.
Operation under "High Altitude Mode" may cause a higher decibel operating noise level because of increased fan speed necessary to improve overall system cooling and performance.
If you use this projector under other extreme conditions excluding the above, it may display auto
However, this is not to state that this projector can operate under any and all harsh or extreme conditions.