I have a Vizio SV470XVT1A I'd like to fix, but am unsure of which part to replace. The screen has a "flicker", which appears to wipe from right to left.

I assume when you say unhooking one of the ribbon connectors leaves half the screen white or black and the other has a picture, if you've replaced he tcon and it didn't fix it your going to find your panel is bad, a main board shouldn't cause your issue as long as unhooking one of the ribbon connectors gives half a picture

Hi John Adams, as you comment, it would seem a failure on the Main Board
Hola John Adams, por lo que comentas, pareceria una falla en la placa Principal

Since it has a high pitched squeal I'd lean towards the power board, if your able take some voltage measurements of the various rails

Sounds like Tcon issues, is the menu normal?

Check and replace the T'Con board. It is faulty. If you wish to get some details; visit the site linked here. Pull up older posts. http://electronicshelponline.blogspot.com/ Faults & possible causes to LCD & Plasma screen are given with illustrations. You can get an idea about the fault to an extent. Faults to all LCD & Plasma screen are similar, irrespective of its brand and screen size.

Fault at its main digital 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://electro-medical.blogspot.com/
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.

42" Vizio TV flickering strobing easy way to repair VW42L ...

? 2:49
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Check and replace the back-light inverter baord.

If you wish to get some details; visit the site linked here. Pull up older posts.
http://electronicshelponline.blogspot.com/
faults & possible causes to LCD & Plasma screen are given with illustrations. You can get an idea about the fault to an extent. Faults to all LCD & Plasma screen are similar, irrespective of its brand and screen size.

Check and replace its main power regulator board as card basis.