Vizio tv no sound or picture?

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.

The led is what makes the picture try replacing that it it's the only one you didn't change out

Fault to the main power supply regulator section. Either it will be a separate board, or the part of main board. Check and replace damaged component/s at its main power regulator [SMPS] section circuit. Contact any service technician. If you wish to get some details; check the site linked here. Pull up older posts.
http://electronicshelponline.blogspot.com/
It will be best to replace the power supply regulator board as card basis rather than making "Surgery" to it; which usually will make loss for both money and time. Even though you can make it right, it will cost around an amount equal to the cost of a new board; including the cost of (spare parts + service charge) More to say, most of the spare parts to it will be difficult to get from open electronic spare part market. This is true to most of the flat panel TV power supply boards; irrespective of its brand and screen size.

backlight inverter

Fault to its main board. Short circuited component/s at it. Contact any service technician; or the authorized service center. If you wish to get some details; check the site linked here. Surf the site with patience. Pull up older posts. http://electronicshelponline.blogspot.com/ . In most cases, the main board might have to be replaced. If so, a software [firmware] update too might be necessary.

First check main boards,
From Wisiny.com can find those parts,power supply,inverter boards and t-con

Check the incoming power supply voltage to its back-light inverter, from main power regulator board. Check the main power regulator board.

I have been having the same problem with my LG. people say there are bad capacitors on the power supply board. I don't have the know how to replace them and don't have the money to pay. I can get mine to work by blowing hot air with a hair dryer into the back of my tv through the vents over the board. Heat it up for a couple minutes and turn it off and then back on and the picture comes back. I just never turn the set off now.

Im having similar problem and with my limited knowledge of lcd tvs and the voltages ALL being good except the pwr on or sw on voltage from the main board to the power supply which tells it to switch everything on Im guessing that something is going wrong on the main board. In the condition where it freezes it (the power on V) which switches everything on i get varied voltages such as 2.5 or 3 or (the normal 5v) and then when nothing powers up (blank screen) i read 0v on pwr on voltage but all my other voltages are corect (24v to inverter, 12 v to main board, 5v, etc.) Im guessing from researching this is that there is in improper voltage somewhere in the main board circuit. I have been unable to find it so i may order another board and post back.

Do you still get sound? If you do get sound, then the problem can be in the backlight inverter board or in the main power supply that supply 24vdc to the inverter board.