Vizio tv has sound no image

If your Vizio TV has sound but no picture, and you have already done the flashlight test, it may indicate that your TV's backlight or power supply is malfunctioning. Here are some steps you can follow to troubleshoot the issue:

1. Check the cables: Make sure that all cables are properly connected between the TV and any devices you are using, such as a cable box or DVD player.
2. Check the input source: Ensure that the TV is set to the correct input source that the device is connected to. You can cycle through the input sources using the input button on your TV remote.
3. Power cycle the TV: Turn off your TV and unplug it from the power outlet for at least 1 minute, then plug it back in and turn it on again. This can sometimes resolve issues related to the TV's power supply.
4. Reset the TV: Try resetting the TV to its default settings. You can find this option in the TV's menu settings.
5. Contact support: If none of the above steps resolve the issue, it may indicate a hardware problem with the TV's backlight or power supply. In this case, you should contact Vizio support or a qualified technician for further assistance.

I would fault find the power supply.

When you measure the LED voltage where are you connecting your neg lead?

What cable are you connecting to get sound?

You have replaced the led strips but no picture so are the led lights actually lighting up?

Have you performed the flashlight into the screen test to see if you can see a faint picture?

Chances are your T-con may be bad . I would check the backlight by shining a flashlight by the screen to look for an image on the screen . If an image is present, then the backlight is the problem. Your Tcon and main board could be ruled out, if this is the case . At this point check the power board for voltage to the led driver. The leds could have issues.

Your backlight has quit. Yes, it's repairable, but ... how old is it? If it's a fluorescent light, pretty old. You can get inverter modules for it, which is usually the problem, but paying a shop to fix it would be bout the same as buying a new TV with LED backlight.

http://www.shopjimmy.com/vizio/e470i-a0

Pay close attention to the remarks about the led string failing

One or more of the LED backlight strips behind the LCD have failed. Difficult and sometimes expensive to fix.

The led strip is faulty. Normally it's comes with the panel.
If you wish to know bout the Woking of back light LED the check the below added link.
www.electro-medical.blogspot.com

Try the flashlight test for image in a darkened room. If you see image checkout the inverter board.