Turned on TV, heard a pop, now screen won't come on and power button flashes three times

The most common problem that will cause that in this set is the flyback transformer. Often times when it goes out it will take out the horizontal output transistor (h.o.t.) Of course it is impossible to tell for sure w/ out checking some components and doing some tests first, but most of these that we have worked on has been a bad flyback and shorted h.o.t. The flyback would probably cost between $20 - $30 and the transistor would just be a few dollars. Most repair shops would get between $100 - $150 to replace these parts, if that is indeed the problem.