Casio HK1223 - Manual (Page 132)

8-6 Troubleshooting
Display Problems
Nothing appears on the screen.
If the power-on indicator is not on, check the electrical outlet, the
plugs and power cords.
If the power button does not respond to a light touch, press the button
firmly.
If you are using battery power, make sure that it has a charge
remaining and that it is installed correctly.
During operation, the screen may automatically turn off as a result of
power management. Press any key to see if the screen comes back.
The brightness level might be too low. Increase brightness by pressing
Fn+F6 .
The display output might be set to an external device. To switch the
display back to the LCD, press
Fn + F9 , or change the display through
the settings in Display Properties.
Reset the computer by pressing the keyboard BIOS reset switch on
the left side of the computer or by pressing
Ctrl + Alt + Del keys.
Try turning the computer off, wait for a few seconds, then turn it back
on.
The characters on the screen are dim.
Adjust the brightness and/or contrast.
Bad dots appear on the display at all times.
A small number of missing, discolored, or bright dots on the screen
are an intrinsic characteristic of TFT LCD technology. It is not
regarded as a LCD defect.
Resolution cannot be adjusted to desired setting.
Make sure that the video driver is installed correctly.
The external monitor displays nothing.
Make sure that the monitor is turned on.