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Joe, Technician
Category: TV
Satisfied Customers: 7251
Experience:  ASE cert tech for over 12 years, electronics has been my highest study, 4 years of home electronics
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I have a Vizio VL470M. Recently, it stopped working with HDMI

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I have a Vizio VL470M. Recently, it stopped working with HDMI cables, first the audio went out and then the picture as well. I tried three different cables in all four ports with both a cable box and a PS3, so I'm certain it was the tv and not the cables, ports, or devices. The tv continued to work with the cable box through a coax cable for a few days until the screen began flickering to black, and then quit altogether but the sound continued to work fine.

I shined a flashlight on the screen and do not believe that this is a backlight issue. I also tried all the normal tricks of unplugging all the cables, holding the power button, etc.

After some research I assumed the inverter board needed to be replaced, so I ordered a new power supply board through ebay (apparently the inverter is built into this board). I just replaced the power board and the tv appeared to be fixed - it flickered a few times and then worked perfectly through the coax for a few minutes until I tried the HDMI cables again. It gave the same HDCP error message as before, then began flickering to black progressively worse until nothing just like before. It is still occasionally flickering on, but is black almost all the time.

I'm out of ideas except that my HDMI cables killed the brand new board immediately, which would be unlikely since they worked with the tv for years previously.


Thank you for using, my name is XXXXX XXXXX I will be happy to assist you with your concern today.

One thing I always wish to try and do is let you know if something comes up and I am not able to reply back right away but this is sometimes something I cannot avoid. I will always try to reply back to you right away however please understand that I may be busy answering another customer back and thus it may sometimes take time to reply back to you. As soon as I return I will be sure to reply back to you as soon as I am able to.

Most likely coincidental. Usually that's the main/input board that failed.

Can you please try composite red/white/yellow and see if that works?

Customer: replied 3 years ago.

I don't think I have any composite cables here, but the tv is currently black on all inputs regardless of whether a cable is plugged in.


Please understand that all inputs means hdmi and component and composite and rf coax and s-video not or.... so without that it makes it hard to diagnose.

However with that said, did you find any blown fuses within the tv?

I'd say that from your tv's symptoms that 9 times out of 10 the symptoms result in the main/input board being what is bad and needing replaced. Generally if it is power supply related the sound will not even work among other things as well.

The fact that it came on after replacing it I think you possibly just got lucky and from it sitting possibly worked for a short time again... doesnt mean that but most likely. You could have one problem on another board taking out the other which can very well happen that more then one board end up having to be replaced, thus making things much more complicated.

If you need any further assistance you can reply back at any time for my help.



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Customer: replied 3 years ago.

Thank you. I didn't see any blown fuses but I admit I probably don't know what I'm looking for in that department.


I was afraid that the main board might be the problem. I am having trouble finding a replacement board, other than one for $180 dollars on Would you have any suggestions on where to find a more reasonably priced one?


The only other cheaper would be on, you can try

Or encompassparts as well.

Usually they are hard to find if at all.

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