Go to this Blog. It "should " solve the problem.
Really, Really simple, do it your self solution !!
Instructions and pictures included :D
Ken , the poster of that Blog writes........"The problem is with the convergence via thevoltage on the
color ray gun tubes that get out of adjustment.
They arealso known as retrace lines."............
This blog covers many makes and models with many
issues solved, just with that one solution
Give it a try, it's FREE and SIMPLE :D
Had very similar problem, that blog helped me save
hundred's of $$$$ in repair costs ! :D
Hope the blog helps you also :)