How long have you had the set for, and when did the problem occur?
Additionally, what is connected to the TV for devices (DVD, cable box, etc.), and do you have the same issue regardless of which you're trying to watch?
Also, when the screen goes black, if you press the MENU button on the TV remote (not the cable box remote), does the MENU come up on screen?
So, neither DISH, PS3, or DVD will keep a picture on the screen correct?
Try this, in a darkened room, shine a flashlight directly on the screen and look very closely at the screen. Do you see a dimly lit shadowy picture on the TV screen?
This means that the backlight inverter have failed in your TV. It is responsible fro lighting up the LCD display panel. If you can see a shadowy picture, then you know that the power supply, T-Con (LCD controller), and LCD panel itself are doing their jobs. Unfortunately this requires service, and there are no resets that will fix this. Average cost for this type of repair is around $125-$150 parts and labor. It may be more cost effective to purchase a new set, but if you'd like to have the TV repaired, you can use the link below to locate a tech in your area:
If this answers your question, please click "Accept", as it is the only way we Experts get paid for our knowledge on the site. Tips and Bonuses are welcome and appreciated!!