Display goes black after 5 minutes

There is a very good answer to your monitor issue found here:

http://www.fixya.com/support/t467725-samsung_lcd_monitor_syncmaster_203b

It appears as if the monitor's back lighting is failing. To test the theory, take a bright flashlight and shine it on the lcd monitor screen when it goes black. If you can see the images that were on the screen before it went dark while shining the flashlight on the screen, then the back lighting is failing. Depending on the monitor, it could have florescent or L.E.D. back lighting, but it's usually more economical to simply replace the monitor with a new better performing monitor, than to attempt repairing the back lighting on the failing monitor.

mark587, Did you shine a very bright flashlight 1" from the screen to try and see the WIN-desktop ?? Even though the screen appears BLACK. Your words above said: JUST CAN'T SEE IT Did you really NOT see anything? Have you seen any of the longer video clips of "LCD Monitor Disassembly" on YOUTUBE? Some BLACK screen "symptom" lcd displays can be repaired for less than $10 in parts. Capacitors! Also check videos on lcd repair. Then get back here to fixya and I or any of the guys can help you decide what to do with your display whoose screen is now dark and lifeless. After doing the YOUTUBE thing you may even tell us what you will do!!! Hope this was helpful. Yes we do want to hear back from you. please rate this response on fixya. I'm louie12fix on fixya or lmistyrel @ aol.com. Bye for now.

get a bright light or torch and shine it on the screem if you see any faint image then the problem lies with your backlight, sometimes connectors come loose and thats your best hope. if you have a warranty of any kind its time to use it.

just a big hardware problem in your monitor

Check your backlight settings, Power Settings, etc.....

You may have Vista (vista has other power settings such as a custom sleep mode which can fail sometimes to work properly with some hardware/monitor configurations).
So Disable any unconventional Hibrid Hibernation options k!

there is an hardware issue in your lcd it needs to change one of the capaciter please take it to a lcd technician
thanks

I used to repair LCD monitor from Dell. It works for me. You might be using these following steps to examine what wrong with your monitor. After you turned PC on and monitor stopped working or went black, you have to check that if you can see the image on the screen or not by shining a flashlight into the screen, not directly but find the best angle to the screen and take a look very closely. If you can see the icons or any image (Start menu), there will be a minor problem. This is because of CCFL lamps inside screen. Some of them were broken and it is very easy to replace. If you cannot see anything on the screen, there'll be some problems with inverter board. If you have soldering tool and want to fix it by yourself, check the caps first. It may cause this problem. Some caps might show leaking or burn spot on the board because of too high temp. If you don't have soldering tool, you better go get a technician to do so. Hope this help!! If anything I can help you with, feel free to let me know.
Thank you.

Hai,
Do you see any dull image on the screen ?
If yes the inverter Card/Backlight of the screen is having problem.

Regards,
Aby

IF there is no display even with a flashlight, the P/S board is malfunctioning. Bad capacitors or LCD driver board circuit. Mine did this and it was bad caps, 4 of 8 were bad and a burned out chip on the P/S board.