Television and Home Theater

Hello,

 I have a Panasonic PT-42P1 Computer monitor. Its a 42 inch plasma screen and its about 8 or 9 years old. It probably has about 10,000 hours on it. However the picture on it is as crisp as my new Sony XPR2 40 inch.

My 4-year-old 57" Sony KP-57HW40 HDTV has suddenly developed green swishing lines that distort and obscure the picture. You can see elements of the picture in the sweeping lines, but it is nearly unwatchable.

 I have been quoted $500-600 to repair this problem. My questions are:

The small red light on the front of my set stays on and the tv will not turn on Worked fine saturday evening turned it off . Sunday morning ..no more worky..lol ? Anny feedback?