Samsung LED UA40F6400 sound but flickering picture

SOURCE: Ghosting, Flickering, Green Sparkeling Lines, Color Washout.

I had a similar problem on a different monitor and fixed the green sparkles by selecting a lower refresh rate.

SOURCE: Samsung 940 BW Monitor Not working (Black screen)

Hi...there,
That's indicated your backlight inverter are busted. Need to replaced a new one or repaired it. To repaired look for a bad capacitors with a bulged on top of each caps. Not sure, just replaced all the caps... Have a nice weekend!

SOURCE: Samsung 226bw visible flickers just after it is turned on

You may have a faulty inverter or loose power inverter connection. OR
You may have a defective CCFL backlight, it may have the following symptom: Screen flashs on red/pink and off. Picture stays on in red and slowly be come normal. Picture flickering with dim display or appear black. Picture flickering on and off. All these symptoms indicate that the LCD backlight lamp (CCFL Lamp) has reached the end of the life and all you need to do is replacing the CCFL lamp.
Connect an external monitor to your laptop and power the monitor up first then the laptop, if you see the normal Windows images then the video card and laptop is OK and the problem is definitely the backlight. Dim image and/or dark display on the laptop's LCD screen indicates a faulty LCD backlight and it could be the inverter that supplies high voltage to the CCFL lamp or it is the CCLF lamp is nearly burnt out or burnt out, most likely this is the case.
The inverter can be replaced easily but the CCLF lamp is more time consuming and requires soldering skills.
Check out
www.lcdparts.net

SOURCE: 32" Samsung TV, No Power or Sound, power LED on, flashes 3 times

Most likely the set has lost vertical sweep or the feedback from that circuit. This will shut the set down to prevent a horizontal line from burning the face of the CRT. This will have to be looked at by a technician.

SOURCE: Samsung DLP 42" flickering green screen

Just unplug and plug back in. Worked for me.

Try it a few times.

May not work for everyone.