Model
SyncMaster 723N 
Check List
Before calling for assistance, check the information in this section to see if you can remedy any problems yourself. If you do need assistance, please call the phone number on the Information section or contact your dealer.
Symptom
No images on the screen. I cannot turn on the monitor.
Check List
Is the power cord connected properly?
Can you see "Check Signal Cable" on the screen?
If the power is on, reboot the computer to see the initial screen (the login screen), which can be seen.
Can you see "Not Optimum
Mode","Recommended mode 1280 x 1024 60 Hz" on the screen?
Solutions
Check the power cord connection and supply.
(Connected using the
Check the signal cable connection.
(Connected using the DVI cable) If you still see an (error) message on the screen when the monitor is connected properly, check to see if the monitor status is set to analog. Press 
button to have the monitor
If the initial screen (the login screen) appears, boot the computer in the applicable mode (the safe mode for Windows ME/XP/2000) and then change the frequency of the video card.
(Refer to the Preset Timing Modes)
Note: If the initial screen (the login screen) does not appear, contact the Service Center or your dealer.
You can see this message when the signal from the video card exceeds the maximum resolution and frequency that the monitor can handle properly.
Adjust the maximum resolution and frequency that the monitor can handle properly.
If the display exceeds SXGA or 75 Hz, a "Not Optimum
