My Pioneer SD-P5183 Rear projection TV... HELP!!!

[mrgumshoegrouch]

I have a pioneer model SD-P5183Rear projection TV that won't converge horizontally under the convergence menu on the TV. It shows a cross in the middle of the screen and the vertical lines on the cross are separated into three lines that go red green blue from left to right. When adjusting the convergence you can only control the lines vertically but not horizontally or left to right... Help me out I hope it's a simple fix...