Clevo NB55TK1 User Manual page 211

Problem
No image appears on the external
monitor I have plugged in and powered
on.
Nothing appears on screen.
You forget the boot password.
If you choose to set a boot password, NEVER forget your password. The consequences of this could be serious. If you cannot
remember your boot password you must contact your vendor and you may lose all of the information on your hard disk.
Possible Cause - Solution
You haven't installed the video driver and configured it appropriately from the
Control Panel. See Appendix C
the video driver.
The system is in a power saving mode. Toggle the sleep/resume key
combination, Fn + F12 (see
The screen controls need to be adjusted. Toggle the screen control key
combinations Fn + F8/F9. If you're connected to an external monitor, make sure
it's plugged in and turned on. You should also check the monitor's own
brightness and contrast controls.
The computer is set for a different display. Toggle the screen display key
combination, Fn + F7. If an external monitor is connected, turn it on.
The screen saver is activated. Press any key or touch the TouchPad.
If you forget the password, you may have to discharge the battery of the CMOS.
Contact your service representative for help.

Password Warning
Problems and Possible Solutions 7 - 9
Troubleshooting
for instructions on installing and configuring
"Configuring the Power Buttons" on page 4 - 9).
7