I have a HCL473W with a 'concave' screen effect on 2 colors??

I have a HCL473W with a 'concave' screen effect on two of the three colors. I read a number of peoples comments that the IC's were the problem on the convergence board, however, from reading on here, it appears that the IC's aren't even on the convergence board?? It appears that they are on a sub board, is it possible that people have been referring to the sub board as the convergence board by mistake? I don't want to buy the sub board ($140) only to discover that the problem was actually on the convergence board, which is really a 'card' in a shielded case? I do have the original remote and, I only watch about 1 to 2 of hours worth of TV a week! That basically means since I have had the TV for five years, it has about 500 hours of use!! I would have said that wasn't a good life for a TV?? Especially as we also have an old Philips CRT thing that has, I estimate, seen in excess of 15,000 hours of use and still works!