Image too big for screen

Check button on remote that says Zoom/ Aspect ratio, press it repeatedly to get proper setting of picture in screen.

Well this is an LCD projection TV and it sounds like one of the polarizer filter has gotten out of place so you are seeing at the top of your screen the unfiltered image of the LCD panel.
Will need to go into a shop to get repaired. Call and get an estimate of repair. Actually shouldn't be too bad of a repair cost.
Blessings,
A/V Media Tech Guy

Good Day,
Your Optical Engine is going bad. Call a Sony Authorized Service Center. Most are covered even beyond the warranty period.

Good Luck, BIG IRISH.

remove the two small covers left and right behind the front lower panel.remove front lower panel (its a firm fit) pull in this sequence 1 rht top, 2 left top, 3&4 lower mid. lamp behind a panel just to the left of cantre, remove two screws locating it in place .pull lamp housing out

If you are using dishnetwork there is a button that changes the "zoom" on screen...there are 3 settings. The button on the remote says "format"

The Optical Block Assy would have to be replaced, same part that causes Blue Dots, not considered to be user replaceable.

I had the same and replaced the lamp - made a big difference. Got the bulb on Ebay for $82.00 with free shipping. Just the bulb without housing, seller has instruction online for changing bulb - very easy. River Valley Electronics
Here's a link
http://cgi.ebay.com/XL2100U-XL-2100U-A-1606-034-B-A1606034B-LAMP-FOR-SONY_W0QQitemZ370154719357QQihZ024QQcategoryZ149975QQcmdZViewItemQQ_trksidZp1742.m153.l1262

it might sound strange but i think the screen has dropped. I have seen this happen before, is it just one line or 2 as the screen is fitted in the shield, its held by a thin rubber sometimes it can drop when the tv is being moved about or in a lot of vibration like moving it about in a car. now this may sound strange but the last time i fixed one i used 6 match sticks and clean them up and put them in the screen housing and it keep the screen in place after that. but beautiful when removing the screen case as you can inadvertently damage the screen, the screen is only a thick as a bit of cardboard. i suppose you could even put the tv upside down on the bed or something soft and wiggle the screen back into place. this would not damage thew tv and you will not have to take it apart.

hi there, you may have a power supply section trouble, check the biggest electrolytic capacitor in the power supply, the rectifier diode, the regulator, and check for some cold solder, do some test, there is a part to be repalced. ty

Sounds like you have a problem with the high voltage regulation or the power supply. This condition is called "blooming" Stargazer