BenQ Th681 Digital Projector User Manual

Operation 41
Function Description
Picture ModePre-defined picture modes are provided so you can optimize your 
projector image set-up to suit your program type. See Selecting a 
picture mode on page 27 for details.
Reference 
ModeSelects a picture mode that best suits your need for the image quality 
and further fine-tune the image based on the selections listed on the 
same page below. See Setting the User 1/User 2 mode on page 27 
for details.
BrightnessAdjusts the brightness of the image. See...

Operation 42
Function Description
Quick Auto 
SearchSee Switching input signal on page 24 for details.
Color Space 
ConversionSee Changing Color Space on page 25 for details.
Presentation 
TimerReminds the presenter to finish the presentation within a certain time 
frame. See Setting the presentation timer on page 30 for details.
LanguageSets the language for the On-Screen Display (OSD) menus. See Using 
the menus on page 21 for details.
Projector 
InstallationThe projector can be installed on a ceiling...

Operation 43
Function Description
Operation 
Settings
Direct Power On
Allows the projector to turn on automatically once the power is fed 
through the power cord.
Signal Power On
Sets whether to turn the projector directly on without pressing 
POWER or ON when the projector is in standby mode and the signal 
is feed through the VGA cable.
Auto Power Off
Allows the projector to turn off automatically if no input signal is 
detected after a set period of time. See Setting Auto Power Off on 
page 47 for...

Operation 44
Function Description
High 
Altitude 
ModeA mode for operation in high altitude areas. See Operating in a high 
altitude environment on page 32 for details.
Audio 
SettingsSee Adjusting the sound on page 33 for details.
Lamp 
Settings
Lamp Mode
See Setting the Lamp Mode on page 47 for details.
Reset Lamp Timer
See Resetting the lamp timer on page 50 for details.
Equivalent Lamp
See Getting to know the lamp hour on page 47 for details on how the 
total lamp hour is calculated.
Security...

Operation 45
 
Function Description
Standby 
Settings
Monitor Out
Selecting On enables the function. The projector can output a VGA 
signal when it is in standby mode and the COMPUTER 1 jack is 
correctly connected to devices. See Connection on page 16 for how 
to make the connection.
Audio Pass Through
The projector can play sound when it is in standby mode and the 
corresponding jacks are correctly connected to devices. Press  /  to 
choose the source that you wish to use. See Connection on page 16...

Maintenance 46
Maintenance
Care of the projector
Your projector needs little maintenance. The only thing you need to do on a regular basis 
is to keep the lens and case clean.
Never remove any parts of the projector except the lamp. Contact your dealer if other 
parts need replacing.
Cleaning the lens
Clean the lens whenever you notice dirt or dust on the surface. Please be sure to turn off 
the projector and let it cool down completely before cleaning the lens.
•  Use a canister of compressed air to...

Maintenance 47
Lamp information
Getting to know the lamp hour
When the projector is in operation, the duration (in hours) of lamp usage is automatically 
calculated by the built-in timer. 
Total (equivalent) lamp hour = 1.63 x (hours used in Normal mode) + 1.30 x (hours used 
in Economic mode) + 1.00 x (hours used in SmartEco mode)
To obtain the lamp hour information:
1. Press MENU/EXIT and then press  /  to highlight the SYSTEM SETUP: 
Advanced menu.
2. Press  to highlight Lamp Settings and press...

Maintenance 48
Timing of replacing the lamp
When the Lamp indicator lights up red or a message appears suggesting it is time to 
replace the lamp, please install a new lamp or consult your dealer. An old lamp may cause a 
malfunction in the projector and in some instances the lamp may explode. 
Go to http://lamp.benq.com for a replacement lamp.
The LAMP indicator light and TEMPerature warning light will light up if the lamp becomes too hot. 
Turn the power off and let the projector cool for 45 minutes....

Maintenance 49
Replacing the lamp
•  To reduce the risk of electrical shock, always turn the projector off and disconnect the power cord before 
changing the lamp.
•  To reduce the risk of severe burns, allow the projector to cool for at least 45 minutes before replacing the 
lamp.
•  To reduce the risk of injuries to fingers and damage to internal components, use caution when removing 
lamp glass that has shattered into sharp pieces.
•  To reduce the risk of injuries to fingers and/or compromising image...

Maintenance 5012. Connect the power and restart the projector.
Do not turn the power on with the lamp cover removed. 
Resetting the lamp timer
13. After the startup logo, open the On-Screen Display (OSD) menu. Go to the 
SYSTEM SETUP: Advanced > Lamp Settings menu. Press MODE/ENTER.  6. Use the handle to slowly pull the lamp out of 
the projector.
•  Pulling it too quickly may cause the lamp to break and 
scatter broken glass in the projector.
•  Do not place the lamp in locations where water might...