Picture is coming in to big for the screen

Probably not worth repairing as it would be cheaper to buy a new tv.

No picture or sound means the main circuit board has failed, in most cases the boards are not repaired but replaced, this is a very expensive repair and so the option of replacing the TV comes into play, factors that affect the decision to repair or replace are the age of the TV, more than 6 years old replace it, less than 5 repair it. The average life of today's flat panel big screens is at best 8-9 years.

Need s to be replaced the main board.

You have a bad connection to the panel or bad caps on the boards. Not something for the DIY'er. High voltages in plasma sets.

Don't know about losing the channel settings but there is a button on the remote in the middle at the top that says "PIX SHAPE". You can change the size of the picture by choosing several different options. Hope this helps. PJ in Mississippi

the amp is being overdriven.

Ocean's Eleven. Best remake movie, I think.
I believe your TV is in "ZOOM" mode for the screen. This will make a 4x3 picture come up closer to fill in the 16x9 screen, but this cuts off the top and the bottom.
Keep pressing the WIDE button on your remote until the picture looks best.
If you have HD channels, the screen mode should be on NORMAL. HD channels will have the 16x9 screen format.

The non-HD channels will have 4x3 screen format. When the screen mode is on NORMAL, you will have the cut off picture on the sides because the 4x3 format will not fill in a 16x9 screen.

on your remote push the arrow key to the right or left side. this should change format and go into customer setup and turn of autoformat

MINE TOO AND SANYO TOOK THIS TV OFF ITS SUPPORT WE SHOULD ALL SUE THIS COMPANY [email protected]

On your remote push "Info" then push right or left to get OFF zoom mode, Cinema view looks pretty good.