Image lost after 5 min turning on the tv, sound was ok.

Your TV is about 5 years old.
If your LCD TV or monitor has stopped working, or is displaying one of the following symptoms, then it's a candidate for some new capacitors
- Flickering screen
- Screen image disappears after several seconds
- Dim screen
- Slow start
- Power LED on, but no picture
- Unusual colors and/or lines
The primary cause of LCD TV and monitor failure is caused by faulty capacitors. You can examine the capacitors in your LCD TV or monitor and actually see if they are bad.
If they appear bulged on top, then they need to be replaced.
New capacitors will solve a host of problems in LCD monitors and TV's and will extend the life of your monitor or TV by several years.
Check the cables, connectors and connections.
Take it to a repair shop.
https://www.youtube.com/watch?v=TR2iWN6b-LY
LCD TV Repair No Power Power Supply Common Symptoms Solutions How to...

also check the power cord wire coming from the back of the tv is loose from the tv side or perfect.

If you have electronics experience - check the power supply and make sure you are getting the correct voltage to your inverter boards and main av board - also do you see any movement on the screen take a flashlight and shine on the screen - if you can see a dark image on the screen check inverter boards and power first.

thanks,

michael

It wouls appear one of the backlights in the screen is cutting out, this will require the screen to be replaced although in certain circumstances, depending on the age & model of your TV, it is sometimes possible to change the faulty backlight independantly. Take it to a repair centre to get an anaylisis of the type of screen it has.

through remote set its brigtness

My LA40A550 Samsung HDTV is 4 months old. It is doing same. That is the red led blinking 2 sec on and then off for ever. No picture, no sound, nothing. just dark black screen. What to do ?

While you have sound, take a flashlight and shine it on the screen, look very close and see if you can see a dark video image.
Let me know what you see.
lone99star

Btw, I’m available to help over the phone in case u need at https://www.6ya.com/expert/jason_77a19afa8d604dee

This sounds like your convergence correction amplifiers have malfunctioned. These Integrated Circuits often burn out after a few years (STK392-110) they can be replaced with a higher version (STK392-150) However it is important to have the biasing circuitry checked to make sure nothing has burnt out as a result of the ICs malfunctioning. If you have a background in electronics you can repair this problem with very little effort, however if you do not have a background in electronics, I would suggest that you have your TV serviced by a qualified TV technician.

 

I hope this helps,

 

Thank you,

 

Shuttle83

Usually that symptom is caused by cracked solder joints on the vertical output IC. As the IC starts heating up, the picture starts breaking up at the top with several "dancing" dark lines appearing, the top scrunches down and then when the vertical quits altogether, the screen goes completely black. A good slap on the side of the TV might make it happen faster or clear it up temporarily. If you have experience working on PC boards then you can resolder the pins of the vertical output IC but if you have never soldered parts on PC boards then allow a qualified tech to handle it for you.

not sure but you could have a bad color wheel i would suggest a service call from your local shop