I have a Sony Bravia KDL-S40A12U have had 3 years. turned off tv and power button constantly 'clicking' on/off. does not power up. Power light flickers at same time as clicking noise. no picture.

There may be a "Power saving" feature on the TV. Check in set-up and adjust time for auto shut off.

It sounds that the main board to your TV has the fault. Actually, troubleshooting to this board is a skilled one, and not a user repairable one. It will be best to contact the authorized service center for Sony. If you wish to get some details, check the site linked here. http://electronicshelponline.blogspot.com/ Pull up older posts. Check the site in 'Mosaic' view. It will make search easy.

From my experience with sony tv it's normal.The set is going through update mode.Leave the set for about 10 minutes and it should be back to normal.

I have a sony bravia kdl 40v 5100 for less than two years and i did not purchased an extended warranty and now my tv is down.
I have no picture, no sound just a black screen when i turn the power on, the power (green) light is lite up and the tv turns off by itself for like less than 30 seconds. I have tried to press as many buttons on the remote control and on the side of the TV to get any message but nothing seem to happen. Any suggestions and solutions? Thanks

Could be the power board or main board defective, but I suggest you do firmware update first. Go to http://esupport.sony.com/US/perl/swu-list.pl?mdl=KDL42V4100&LOC=3#div_pos_30 download the software.

It is On-Screen Display. Press Info " i " button on TV remote so on-screen display will disappear.
Thanks.

Have you tried support at Sony's website or typing in your question at google?

Hold The Off Button for 20 sec should make clicking noise switch off at power and on again should be working

Hello

on your set there is inverter board that is what lights up th backlight on your TV making everything visible that board has went bad.

Thankyou