Timh asks:

"my samsung 43 inch wont turn on. it tries to, it makes the startup sound when i first turn it on then it makes a high pitch sound. it keeps trying to turn on for a while then all three led lights blink. samsungs website said it was the lamp, so i got a new one and put it in but the same thing happens. any ideas? how do i tell if its the ballast or if im just doing something wrong when installing the new lamp?"

Unfortunately, without diagnostic tools of a technician, there probably isn't any way to tell if it's the lamp or ballast.

Have you tried pulling out the lamp and reinserting it to make sure it's in there well? Sometimes it can be hard to get back in. But if you're getting the screws in there nice and firm, it's probably in there correctly.

If you do decide to take a crack at the ballast, there's instructions here on how to replace a ballast.