We have a Samsung flat screen TV which has no picture. Sound is okay. It was running this evening then went black suddenly.
Welcome to JustAnswer!
(Please click on highlighted words) demo of inverter replacement.
First make sure to hit the menu button on the TV's remote while the screen is black. If you have sound, and nothing is there then while the set is on turn a bright flashlight on and shine at angle into the set. Push the TV menu button if you can see a image then your back light is not working. You can also check the transformers they are close to where the wires plug into the panel. Make sure all transformers read the same amount of resistance if not you have found a bad one. Now you will have to check to see if the power supply is sending 24V to the back light. If not the power supply is bad. Cost back lights around 150.00 and power supplies around 100.00.
Here is a link to better understand the inverter. Within the power supply the capacitors.
About how much would it cost to have Geek Squad do the repair?
Geek squad is a little bit more expensive than your local TV repair man; the cost should be between one hundred to one hundred and fifty dollars.