# Help with Vizio M470NV



## combatshaw (Dec 17, 2013)

Hi all,

I have a Vizio M470NV 47" LED/LCD TV that unfortunately has quit on me. When I turn the TV on, I can see a light change in the panel, but no image is displayed, regardless of the source input. When I press the menu button or VIA button on the remote, I can see a change in the panel as the menus are brought up, but still no image. Sound still comes through just fine, however. I use a HDMI cable to connect my cable box to the TV, as well as another for the PS3, component cables for the Wii, and I can connect my laptop using both a VGA cable and HDMI cable.

I have tried unplugging the TV for various amounts of time, to include overnight, but it still does this. I also tried unplugging for 10 seconds, then plugging back in while holding the power button for 10 seconds and still nothing. I have also replaced the main board inside the TV and it still performed the same.

Any thoughts, suggestions, solutions?


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## Done_Fishin (Oct 10, 2006)

Sounds like you have a Backlight / Backlight Inverter problem. 

Do you have any way of hooking up another TV to your TV via one of the TV outputs (RCA jacks, SCART, HDMI or whatever) to see if the other TV can display whatever your TV should be showing ?


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## combatshaw (Dec 17, 2013)

You know, I didn't think of doing that. But I will see about giving it a shot. The LED backlighting still works, when the set is on, I can see light along edges of the panel.


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## Done_Fishin (Oct 10, 2006)

Looks like you have problems on the mainboard then .. Tuner is working since you have sound so the problem is with the signal getting from the Tuner to the graphics processor. Unfortunately I have little experience with LCD TV's and none whatsoever with this particular model. I used to do a lot of TV work so the general principal & diagnosis is not unknown to me.


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## combatshaw (Dec 17, 2013)

I have already tried replacing the main board and unfortunately, the problem was still present. I'm wondering if it could be one of the other boards?


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## Done_Fishin (Oct 10, 2006)

Without some sort of a service manual to see where everything is, it's difficult to say 

It could be power supply, perhaps a lost or wrong voltage,

It could be your LCD Display Panel not getting correct signals .. only by swapping boards from a working unit will you be able to pinpoint what board it is.

One other possibility .. have you tried playing with the brightness/contrast ??


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## TMikels (Oct 19, 2015)

I have a M470NV also. My screen just went dark and says no input available. I have tried all hdmi ports and cable ports as well, nothing. But when i use my wifi, I can watch netflex and all the other apps just fine. I'm thinking its the main board that went out on me. I just needed some input before I purchase a main board.
Thank you
Tom


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