troubleshooting von der ASUS-homepage:
If CODE is A9,it means the computer has entered into BIOS
1. If the monitor is abnormal, please follow below steps to troubleshoot:
a. Please make sure monitor is powered on normally and check the indicator light of monitor is on to ensure the power cable of the monitor is connected correctly. Make sure the external power cable is powered on normally. Please try to switch on, switch off, check if monitor can display. If you switch off and switch on the monitor, monitor shows ''no signal'', it indicates the monitor is powered on normally.
b. Confirm that the signal cable(VGA/DVI/HDMI/DisplayPort) is correctly connected to the monitor, also confirm that the other end of the signal cable is connected to the display output (graphics card) of the computer. Try to re-plug the two sides of the display cable and confirm that all pins are not bent.
c. Confirm that the display output of the monitor is correct. For example, if it currently connected to the computer via HDMI interface , you should choose the display output of the monitor as HDMI display output.
d. Replace the same kind of cable (VGA/DVI/HDMI/DisplayPort) to re-test
e. Connect the monitor to another computer, confirm output of the monitor is normal to eliminate monitor problem
2. If the monitor can display BIOS,please follow
Troubleshootings for Boot up device abnormal, comfirm if the hard disk or SSD is abnormal