Vizio black screen problem I have power with sound but screen is black always, I did flash light test and can see pic dimly so is it a inverter or led?

Ho Joe...I suspect your LED backlights are bad, this model doesn't have local dimming so complete lamp failure is possible. A couple things to test, you need to make sure you're getting the signal to enable the inverter, look for around 3 vdc at the bl-on pin on power board, if you see that chances are really good it's bad lamps and over voltage-current is shutting down the regulator side of the inverter, the reason you see voltage on the 2 B+ lines to frame ground is they regulate the minus side of the supply. If you have a 330 ohm 2 watt resistor you can jump each minus side and you should see the working lamps light but it really doesn't prove anything other than some of the lamps still work

It's possible you have bad LED backlights but before opening up the panel check for cold solder joints on the connectors from the power board to LED driver.

Back - light problem. Check and replace damaged component/s at its back-light inverter board, or replace this board as card basis. If you wish to get some details; check the site linked here. Surf the site with patience. Pull up older posts. It will be best to replace the inverter board as card basis.
http://electronicshelponline.blogspot.com/
To some model sets; especially LED back-lighted types; the back-light inverter circuit will be part of the main power supply board [SMPS]. In such cases, the power supply board might need replacement. To some models sets, the back-light inverter and SMPS section circuit will be integrated at its main board itself. If so; the main board should be replaced. To some models of sets, all these section circuit will be integrated at its main board. If this is the case, you have to replace the main digital board.

Main board.

Check out the flash light test - if you see an image then the issue is with your inverter board that powers the back lighting.

Keep it simple- Use the flash light test to see if you have no back lighting in which case then you have to replace the inverter board. And if it is not that board then your issue probably lies with your t con board.

Check and replace damaged component/s at its back-light inverter board, or replace this board as card basis. If you wish to get some details; check the site linked here. Surf the site with patience. Pull up older posts. It will be best to replace the inverter board as card basis.
http://electronicshelponline.blogspot.com/
Some model sets; especially LED back-lighted types; the back-light inverter circuit will be part of the main power supply board [SMPS]. In such cases, the power supply board might need replacement.

Most likely you have a backlight problem. To verify this, dim the lights in the room. Take a bright flashlight, turn on the set, and shine it on the screen. If you see a faint picture, you have a backlight fault. Your backlight inverter may be built into your power supply board. If this is the case, you will have to replace the inverter/power supply board

Hello,
turn on the set, grab a bright flash light and dim the lights in the room. Shine the flash light on the screen, if you see a faint picture on the screen, you are dealing with a backlight problem. There are several things that can cause this. One, a bad backlight inverter, two, faulty 24vdc power supply, three, bad main board, or a bad faulty backlamp.

There are two places to look for the problems, the backlight inverter board and the power supply. Look at the power supply first since it is easier to get to, look for burnt parts, bad capacitors, etc.
http://en.wikipedia.org/wiki/Capacitor_plague
Parts: http://www.shopjimmy.com/catalogsearch/result/?q=Vizio+VX32L+
Please post back what you find.