I have a sony KDL 46xBR2 when I turn on powers up green light stays on but a dark gray screen no picture or sound

Is the screen cracked at all? This is mostly what causes this type problem. Unplug the television but not before doing a complete factory reset a total rester network everything if this don't help 1 of the displays is going out.

your backlight bulb or circuitry is likely the problem.

Does the front light stays green ? Or goes back to red ? The back-light going on/off maybe the problem, but it shoul return with a red blinking led (4 times ?) and if so it can be a power inverter problem.

would say that the screen lights have gone. usually they flicker for a while then come on. then off etc. more than half the screen has gone so the power from the inverter is not being used so it turns off the tv. it is a very fiddly job replacing them as you can damage the screen in the process. more easyer just to get a new screen.

It sounds like a main board failure but could be a power supply issue as well. The set will need to be diagnosed

Main PCB is bad . I just got the information from a Sony authorize servicer price for the part only $504.87

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

I have

call a tv place and order a lamp for it if your not old to lift it

the screen is on its way out