ViewSonic PX747-4K PX727-4K User Guide English - Page 31

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. Go to the SYSTEM SETUP: ADVANCED > Panel Key Lock menu 2. Press Enter and press / to select On. 3. A confirmation message is displayed. Select Yes to confirm. To release panel key lock, press and hold on the projector for 3 seconds. You can also use the remote control to enter the SYSTEM SETUP: ADVANCED > Panel Key Lock menu and select Off. Keys on the remote control are still functional 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-3000 m above sea level, and temperature is between 5°C-25°C. CAUTION Do not use the High Altitude Mode if your altitude is between 0 m and 1499 m and temperature is between 5°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: Notice 1. Open the OSD menu and go to the INSTALLATION > High Altitude Mode menu. We recommend you use the High Altitude mode by selecting it whenever your environment is higher than 1500m. 2. Press Enter and press / to select On. A confirmation message is displayed. Do you want to turn High Altitude Mode ON? 3. Highlight Yes and press Enter. Yes No 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 shut-down symptoms, which is designed to protect your projector from over-heating. In cases like this, you should switch to High Altitude Mode to solve these symptoms. However, this is not to state that this projector can operate under any and all harsh or extreme conditions. Adjusting the sound The sound adjustments made as below will have an effect on the projector speaker. Be sure you have made a correct connection to the projector audio input/output jacks. See "Connection" on page 14 for more details. Muting the sound 1. Open the OSD menu and go to the SYSTEM SETUP: ADVANCED > Audio Settings > Mute menu. 26