My big screen tv show snow on all channels.

If the picture shows a picture briefly upon power up then goes off after a few seconds, you have a back light fault. It could have a problem in the 24vdc circuit, failing back light inverter board, or a blown CCFL lamp.

you probebly just knocked it off channel............
cheers

This is the best solution for your problem as a 40 year experience with wires etc. Go to the source of your cable signal connector . Open it and clean the terminals with emery paper , sand the end of the cable shiny clean from corrosion , get a new barrel connectors with gold terminals if possible lengthen the ends of the cable , insert and tighten good, use thick rg-16 or rg 40 cable with good insulation ends crimped professionally with a crimpier or buy ready made , not from dollar store. Get a gold plated professional splitter if you need one or two , it will cost about 15 or more each . Make the cable runs as short as possible, using the thick good cables. If needed get a signal magnifier. From radio shack or the source etc. Connect them good and tight . Ground the splitters . Problem solved , you will get crystal clear channel 2 to 7 including 3 and 4 . Isolate the TV cable from other cables and power wires. Vitally

If you go to menu do you get that on the screen?

Does your controller turn the tv on and off?

We had the same thing happen to us on the right-hand side. A technician told us yesterday that the Motorola Cable Box (supplied by Shaw Cable) places a border on Non-True HD Channels. Because we didn't place our picture setting to 'full-screen' each time we viewed these channels and burn line was created. He gestimated a replacement screen runs about $800.00 Canadian, but we have a 3 year extended warranty and will receive a new TV. He also said it happens on all big screen tv's that use a cable box creating borders on Non-True HD Channels.

If you are using Direct TV or Dish Network call their tech support.
If you are on cable TV, call for a service man.
I would say that your TV has lost its sync separater chip and it shouldn't cost more than $60 dollars to fix, if the repair guy is honest. It's a 30 minute job.
This message is from an electronics engineer, retired.

try the RGB or the S-video out of the Direct TV receiver.

If you have a good cable signal connected to the TV and it receives channel 50 nice and clear but all lower channels have nothing but snow, then the tuner is defective and needs to be replaced. This is quite an easy thing to correct. Sometimes resoldering all connections inside the tuner will bring it back to life, but in either case the set should be serviced by a qualified tech.

Hi, I am having the same exact issue with mine. Although, it is only about 2 yrs old. We are still trying to find out what is wrong with it.