Backlight problem syncmaster 940n

SOURCE: Samsung Syncmaster 940n - white screen

I don't think the driver is a problem. This is the way how to examine what's wrong with your LCD monitors. After you turned it on and the screen 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, there will be a minor problem. This is because of the 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,

SOURCE: Brightness indicator windows does not go away

Dear sir This is common problem observed in many monitors compaq,HP,HCL,IBM this is happens mainly in rainy season due to moisture,by this moisture monitor button circuit get rust inside and button pad remain pressed. so it shows a strip at the middle of monitor like contrast or brightness. So this is minor problem just replace the monitor display control button sensor or circuit.Temporarily you can warm up the monitor by hanging a bulb of 60 watt nearer your monitor to takeoff the moisture.(Dont hang the bulb too near to the monitor). It definitely solves your problem.
Have a Nice Day

SOURCE: my monitor 940n samsung syncmaster gone in black...

I have just had this same problem. The problem mostlikely is a blown fuse on the inverter board. Mine was blown on the board and also a Capacitor (470nF/25V) was bad beside the Fuse.

I replaced both and monitor is working now again. After install the picture was a little grainy with little artifacts. In another post i found that the Power Supply board needs to be cleaned for unwanted residue. After that picture was fine again.

BEWARE that you need a soldering iron and a steady hand to replace these parts. If you are unfamiliar with soldering at all have an expert take a look at this. The Power boards uses 220v so DO NOT connect it to the Power when opened.

Starworx

SOURCE: Samsung SyncMaster 940n monitor that turns on then goes black

rcpips, You may need to replace one or possibly 5 -8 aluminum can "electrolytic filter capacitors" on the "switch-mode-power-supply/CCFL inverter board. If, as you say "works for 5 or 6 seconds" then that means that fuse is good. Another thing you will need to inspect SMPS board for is "cold" "frosty looking" solder joints where the components (surface mount or through hole) are soldered to the copper circuit traces. May need large magnifying glass or low power inspection microscope to locate them. Resolder any that look bad or loose. Some solder joints have thinner than "hair" thermal fractures that can also cause YOUR TYPE OF SYMPTOM!! PARTS: digikey. mouser. newark. and possibly Radio Shack. If buying filter capacitors, make sure they are rated 105 deg C only!! NOT 85 deg C!!! If caps need to be replaced (swollen, leaky) be sure to tell us the brand name you find installed on your unit! CAPXON, ELITE, JUN-FU are just 3 that you don"t want to find in your unit. BAD news if you do!! If DIY suits you, remember to document with "close-up" digital stills your unit tear-down, so you can reassemble unit without any "extra" parts laying on kitchen table!! Filter capacitors are polarized. You put them in + to +, - to -!!! if you put them in backwards they go BOOOOMMM!!! Hope this helps a little. lmistyrel on aim or 12fixlouie at fixya.

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SOURCE: SyncMaster 940N - screen has gone dark when turned on...

Sounds like the backlight has failed. The backlight illuminates the liquid crystal display. Without it, everything's black. Though, as you observed, if you get really close you can still see something of the image.