Flashing Logo/no picture even After replacement of Power Board.

The symptoms you described could be caused by a few different hardware issues. One possibility is that the backlight system, which provides the TV's illumination, may have failed or malfunctioned, resulting in the white fog over the screen. Another possibility is that the LCD panel may have developed a fault, which can cause discoloration or uneven brightness across the display. Both of these issues are typically not easily fixable through user adjustments or software updates and may require replacement of the affected hardware components.

I also believe that to further diagnose the issue, you could try connecting an external device, such as a game console or DVD player, to the TV and see if the white fog and black background issue persists across different sources. If the issue is present across multiple sources, then it is likely a hardware issue with the TV.
If the TV is still under warranty, you may be able to get it repaired or replaced by Vizio.
It's also worth noting that in some cases, the issue may be caused by a faulty T-Con board, which is responsible for controlling the timing and signals that drive the LCD panel. This is another potential hardware issue that can cause issues with the display.
Do notify me if the solution helped, I will be glad to help you more.

It sounds like you have already done some troubleshooting on your UN65TU7000FXZA TV. Based on the symptoms you described, it's possible that the issue may be with the backlighting system or the T-con board.
Here are a few steps you can try to further troubleshoot the issue:

1. Check the backlighting: Shine a flashlight on the screen and see if you can see any images. If you can see faint images, it's possible that the backlighting system is not functioning properly. In that case, you may need to replace the LED strips or the power supply board for the backlighting system.
2. Check the T-con board: The T-con board controls the timing and signals for the display. If this board is not functioning properly, it can cause issues with the display. You can try replacing the T-con board to see if that resolves the issue.
3. Check the capacitors: Faulty capacitors on the power supply board can cause issues with the TV turning on and off. Check the capacitors on the power supply board to see if they are swollen or leaking. If they are, you will need to replace the power supply board.
4. Check the cables: Ensure that all cables are connected securely and there are no loose connections.

If none of these steps resolve the issue, it may be best to consult with a professional TV repair technician or contact the manufacturer for further assistance.

Usually the flashing red light would be transmitting a blink code that would at least provide a strong clue to the nature/location of the fault.

The symptom you report seems to be fairly common and a quick search produced others searching for the meaning of the blink code but I saw no firm answers.

As the logo appears on screen, albeit briefly, it would suggest there is power and a good screen. A common design of the modern tv is the screen remaining black unless there is a signal to display, even self-generated signals such as menus, so perhaps the source of the problem is a fault that is preventing signal from reaching the video amplifier and scan section.

I have read during my search of people trying to fix the problem themselves and ended up spending the cost of a cheap tv and it still not working. As you are on a tight budget you need better value than that and that means a professional repair from somebody with experience, test gear and access to service manuals.
If I was in your position I would seek a friendly local repair guy and ask how much the cost is likely to be and then you can decide...

Yes. Sounds like the power supply is shot. However that being said do not be suprised if after changing the power supply you find that the main board is gone out as well. Take the cost of that board as well into consideration before repairing. My insignia did the same thing and parts alone were more than the set was new...fortunately mine was under warranty.

If your LCD TV or monitor has stopped working, or is displaying one of the following symptoms, then it's a candidate for some new capacitors
- Flickering screen
- Screen image disappears after several seconds
- Dim screen
- Slow start
- Power LED on, but no picture
- Unusual colors and/or lines
The primary cause of LCD TV and monitor failure is caused by faulty capacitors. You can examine the capacitors in your LCD TV or monitor and actually see if they are bad.
If they appear bulged on top, then they need to be replaced.
New capacitors will solve a host of problems in LCD monitors and TV's and will extend the life of your monitor or TV by several years.
Check the cables, connectors and connections.
Take it to a repair shop.
https://www.youtube.com/watch?v=TR2iWN6b-LY
LCD TV Repair No Power Power Supply Common Symptoms Solutions How to...

If your LCD TV or monitor has stopped working, or is displaying one of the following symptoms, then it's a candidate for some new capacitors
- Flickering screen
- Screen image disappears after several seconds
- Dim screen
- Slow start
- Power LED on, but no picture
- Unusual colors and/or lines
The primary cause of LCD TV and monitor failure is caused by faulty capacitors. You can examine the capacitors in your LCD TV or monitor and actually see if they are bad.
If they appear bulged on top, then they need to be replaced.
New capacitors will solve a host of problems in LCD monitors and TV's and will extend the life of your monitor or TV by several years.
Check the cables, connectors and connections.
Take it to a repair shop.
https://www.youtube.com/watch?v=TR2iWN6b-LY
LCD TV Repair No Power Power Supply Common Symptoms Solutions How to...

If your LCD TV or monitor has stopped working, or is displaying one of the following symptoms, then it's a candidate for some new capacitors
- Flickering screen
- Screen image disappears after several seconds
- Dim screen
- Slow start
- Power LED on, but no picture
- Unusual colors and/or lines
The primary cause of LCD TV and monitor failure is caused by faulty capacitors. You can examine the capacitors in your LCD TV or monitor and actually see if they are bad.
If they appear bulged on top, then they need to be replaced.
New capacitors will solve a host of problems in LCD monitors and TV's and will extend the life of your monitor or TV by several years.
Check the cables, connectors and connections.
Take it to a repair shop.

I would suspect the main board as well

Hello,

The black display and blinking power light indicate a failure of the power supply filter capacitors. This is a common issue on LCD monitors after a few years of use. The repair is easy to do you will need to open the unit and replace the bad capacitors on the power supply board. Here is a link to an article explaining what capacitors are and how to locate the one that failed on the power supply board.

http://www.ccl-la.com/blog/index.php/capacitors/

It is a very common problem not only on LG TV's but almost all brands of LCD TV's. The caused of these symptoms is a faulty electrolytic capacitor on the power supply board.

See sample video below.





Time will come that the symptoms will get worst, the unit will not even power up.


You have to replaced the faulty caps on that board to resolve the issue or replaced the entire power supply board. Check on ebay.com for the board.