Must turn monitor off/on coming out of sleep mode

Sounds to me it could be a burnt or illegible ram memory card in your laptop, try taking one of them off, or switching one of them to the other slot just to troubleshoot.

Hope this helps you.

Is this a laptop?
This a common problem for monitors, especially on laptops. This cause by the inverter board. The inverter boosts voltage to light the screen. When goes bad they go bad they often work for a few seconds. If you look closely you can see the screen but the voltage is not there to get brightness.

That means your monitor is not receiving a signal from your video card.

A couple things to check:
*Make sure your cable is ok - unplug and replug the cable to see if it is a loose connection. Or try a different cable.

*Make sure your computer is not in sleep mode - Move your mouse or otherwise ensure your computer is awake and sending a video signal

*If you have another computer, try the monitor on the other system and see if it works.

Look for bulging capacitors on the board and replace with the same type. Have a repairman help you.

Robbert_R_V, Have you visited YOUTUBE to search out and view some of the longer video clips of "LCD monitor disassembly" or "LCD monitor repair" or www.ccl-la.com/badcaps.htm site run by "buddymc" on fixya. Do that first!!! FYI !! Also try www.lcdparts.com for some additional info. Here is a hint of a similar TECHNOLOGY that you are dealing with. Have you seen the CURLIE-Q energy-efficent CFL light bulbs at the homecenter stores? They have what is called an ELECTRONIC BALLAST circuit called a CONVERTER! AC to AC. You have a ballast called an INVERTER. DC to AC 800v to 1200v to light-up your thin, straight, tubes hung on the backside of your LCD glass panel! If this info was of some help, please rate this response on fixya. Bye for now. 12fixlouie

i have the same problem

I think it maybe time to buy a new monitor

If you can still faintly see data on your screen, it will be a faulty backlight in the panel most likely.

LCD panels have fluorescent tubes in them that provide the light needed to see the data. If one of these goes faulty, the circuit that drives it will turn off ALL the backlights, giving you a black screen.
Note: a faulty circuit that drives the backlights will often give the same apparent fault.
You will need to take the monitor in for repair.

connect the monitor to pc and press the power button to make it to the power on mode. you must have used your keyboard to make it on sleep mode.