Sony KDL46-nx700 LCD TV comes on with good picture and sound but the controls for all functions don't operate using remote or onboard controls TV. TV switches itself off after about a minute.

SOURCE: Sony Grand wega KDF-E50A10

unfortunately the B Box assembly needs to be changed in these and price of the part alone is more than half the cost of a new tv

SOURCE: CRACK LCD TV SCREEN

I don't have a listing for your model, but it is not unusual for the panel to cost more than a replacement set. As another example, the replacement tube (CRT) for a 27" Sony set can easily be $700. This was when these sets were being sold for $350!! Parts is where these companies rake in big profits. Don't blame the servicer for this one.

Sorry about the bad news.
Dan

SOURCE: Remote Codes for new Sony Bravia

Sony has unique code for all equipments, those are 0000, and 0111, if doesn't work with your tv the problem it is on the remote control.

SOURCE: Sony Bravia KDL 52 keeps turning itself OFF

i had prob where my sony would switch off for a few secs thenh come back on . The solution was in menu / tv settings / sleep timer . Go into that and make sure its set to off. there are opions for off , 5 min 20 min 30 min etc... mine was set to nothing just blank.

SOURCE: I have coloured vertical lines covering my Sony

I also have a 2 yr old Sony KDL32xbr4 that now has multi-colored vertical lines on the screen. I contacted Sony and they say they have "no known issue" of this sort for this model. I find this rather puzzling since I have found numerous postings on the web. They told me to try the factory reset. Whatever. Might as well have said "don't buy a Sony". 2 years! $1300 for a tv and it lasts 2 years! Makes me sick to my stomach.