40xv645u turns on now has sound no light on screen no black light just dark

SOURCE: The LCD screen is dark with no sound or picture when turned on.

I had the same problem after having a Vizio for 2 and a half years. I left the room for a minute, i came back and the screen went black. There was still power to the unit and you could see that the back light was working, just no picture, no sound, and you couldn't use any of the buttons. The only way to turn it off was to unplug it. It would then start up, with the Vizio logo going from orange to white, and then do the same thing all over, no pic or sound.

HOW I FIXED MINE:Look through the back vents for a white light to make sure the backlight still works. I ordered a new "main PCB" from tigerdirectparts.com (you can also use searspartsdirect.com). This is the circuit board with all of the inputs on it (hdmi, cable, etc.) I opened it up, disconnected the old one, put in a new one and now it works fine. I used both serial numbers on the board to search for it online. It cost me $144 to do it, but that's better than $450 for a new TV. My tv is the vx32l hdtv10a. I hope that helps.

For me the part number was either (depending on the vendor) : 0171 2272 2174 or it was 3632 0212 0150. Check your circuit and see if any of those numbers match up.

SOURCE: Power on - Screen Black non responsive

U might get the tv working again,by unpluging it,replug an hour later let the tv reset it self.Not,Than the Tuner board,it the board u should looking into replacing.Not the power supply board is good,because u getting a solid power LED indicator light.

SOURCE: Screen is black after the initial white screen

I believe a firmware update can fix this issue. However to be sure I would need your entire model number, including the numbers after the slash. You can put that entire model number into Philips support website, http://www.usa.philips.com/#/headernav/consumer/

Once you get to your TV's support page, you can look on the right hand side and find the firmware information. First I suggest you read the Read Me file to familiarize yourself with the update process and what issues it fixes. Then you can download the firmware to your computer so you can upload it to a USB drive to perform the update.

Hope that helps!

SOURCE: Turn tv on. green light solid display, no picture or sound

The flashing green light is likely indicative of a self-test failure, indicating the TV has detected some sort of internal fault. With no picture or sound, one strong suspect is the power supply. Flat-panel TV's have an internal DC power supply that converts the inbound AC current, and when these fail, or are unable to supply a minimum level of power to the set, it can behave as you describe, providing only enough power for the green light to illuminate.