Help with Panasonic plasma TV's display shift. I have a Panasonic Plasma Model TH-42PX25 bought

Question

I have a Panasonic Plasma Model TH-42PX25 bought about 4-5 yrs ago.I have Comcast service and use the cable box. Not sure what happened but the picture image on non-HD has shifted about 2-3 inches left. Changing the aspect ratio does not help much as the left side is chopped off all the time. All the HD channels work fine with nothing being chopped off. Playing a DVD does the same thing. Between the Cable box and TV there is a Yamaha speaker bar which I go through. However, I ran the cable box to the TVs front Input 3 (bypassing the yamaha speaker) and still the video issue persists. I have even reset the TV with power and OK button combo as suggested by Panasonic support but that did not help either. I would like to hear your opinion on what is wrong? Is the next step to call some repair person to help diagnose and fix it? If so, who can be recommended? I live in Fremont, CA.Please help.Thanks,Shailesh [e-mail]