Samsung hcm4216 rear projection

I have a blue shadow/bar across the top and arching half way down the set, Ive researched other projecion tv's and found that the blue convergence board seemed to be the problem. I've checked my model and i dont see convergence boards. On the list, there is a (picture tube for blue). Does that sound like what I need? It's $271.00 Is it resonably easy to replace? thanks. Dan. p.s. here's the parts list for my model http://www.samsungparts.com/search/search.asp