Why does the sound on my tv have static when watching DVD's?

My kids left our plasma TV on overnight after watching DVDs. The next morning, there was no picture but there was sound. Could the pixels have worn out that quickly?

• Answer:

  Assuming it was a fairly new television and not several years old: no. All televisions are consumer electronics. All products can fail in normal use, because the manufacturing processes cannot make them perfect. A certain percentage will always fail short of their expected life. If you are lucky, they will break down while still under warranty. The warranty period is often a reflection of the quality of the product: a six-month warranty provides no support apart from components that are immediately defective, while a 20-year warranty implies a quality product that is well-supported by the manufacturer (yes, one company that I know of sells audio equipment with a 20-year warranty). The television could have failed for any number of reasons. The pixels don't all suddenly fail when they wear out. Instead, you see a gradual deterioration of the image, as enough individual pixels fail to affect the appearance. Colour shifts are also experienced. Your failure is more likely to have been caused by a problem in the power supply to the plasma screen. When there is a total failure of that nature, it usually means the problem lies in some part of the uit that supplies power to the subassembly or controls it in some fashion. A picture tube could loose its seal, causing a total failure, but a plasma screen has a seal for each plasma element. This makes a total failure unlikely, unless the entire screen has come apart.