I bought a 51" HD ready Progressive Scan (51mp392h/17) TV about 2 years ago from Circuit City. Just today, the blue gun is off causing blue shadows on the screen. If I go to the convergence menu, I can move the blue left & right, but not up & down. Additionally, the blue seems correct in the upper left quadrant of the screen. At the bottom, it seems to arch up in the middle. In the upper right quadrant, it is way off, up and to the right. The red convergence works correctly. Is this something I can troubleshoot and fix myself? I'm an old EE, now Computer IT/guy so replacing modules and/or soldering is not out of the question. Are there service manuals available on the web somewhere?
Any help/guidance/pointers would be greatly appreciated.