How to Fix your Vizio M470NV and M550NV

[hardbox]

Hello Nick, I have a Vizio XVT3D424SV that shows no picture at all. The LEDs will come on. Done the diagnose by disconnecting one of the two ribbons between the T-con board and the panel. Still not picture. Do you think it is the mainboard and will a reflow help?
Thanks

I think is the Tcon is bad.

[hardbox]

Most likely is a Tcon issue..

[Nick's Tvs]

Re: How to Fix your Vizio M470NV and M550NV

Hardbox,

We do not have a test set to test that specific T-con board at this time, so I wouldn't be able to check it for you and or repair it if indeed it is at fault. We have been seeing and getting more requests to service these T-con boards however as they do seem to be failing more often on the models ending in 4SV.
I do believe you are correct however and that your T-con is at fault. If you would like to send in your Main board to get checked, we can definitely do so as we do have a proper test set for the main board.

[Andrew F. Ali]

Re: How to Fix your Vizio M470NV and M550NV

I concur that the T-CON Bd is the fault, also. In my experience Main Bds do fail sometimes by not sending LVDS to the T-CON Bd., but very rarely.

[SILVAMANE]

Re: How to Fix your Vizio M470NV and M550NV re.

Vizio M470NV. Nicks TV I'm having this same issue. My TV gets power ,the vizeo symbol stays orange. Click the power button with no change.remains orange. Tried unplugging it and holding power button for 30 seconds and plugged back in ad tried again and still no change. Which of the 3 boards should I change. The main board,power supply or the t con? Please help. I know this is an old post but hopefully you can help. Thank you so muxh your info is very infor native.

[Nick's Tvs]

Re: How to Fix your Vizio M470NV and M550NV

Hello Silvamane,

If you take a look at your symptoms, and match them up with the detailed post at the beginning of this thread, you will find your answer.

To make it easier for you however, this thread is only in regards to main board failures, and your symptoms do match with one of the several symptoms listed. You do have a faulty main board.

[JDC]

Re: How to Fix your Vizio M470NV and M550NV

Nick,

Thank you for this post. Really informative.

Thanks,

JDC

[ivtec]

Re: How to Fix your Vizio M470NV and M550NV

I fixed my Vizio M421VT LED that would have a symptom of pic scrambled, i heated the BGA with a Heat Gun both sides of the board and added 2 fans 5 v dc on the back against the BGA and it's been good ever since.

My M421Vt still works great till this day after i've done the above procedure

[kd6mtw]

Re: How to Fix your Vizio M470NV and M550NV

Hey there Nick,

I have symptom #7 orange logo and no power. I am not seeing the 12v coming off the SMPS board but I do see the 5volts. Could this still be the main board? M470NV

[Nick's Tvs]

Re: How to Fix your Vizio M470NV and M550NV

Yes that is still the main board. It is normal you are not getting the 12v, the 12v will only come up when the TV turns on.

[Jimmypooh]

Re: How to Fix your Vizio M470NV and M550NV

Has anyone found the transistor needed for repair option 1; Q29? I don't do too much transistor work or surface mount stuff, but do a fair amount of soldering in my hobbies and wanted to give this a try. Thanks!

[Nick's Tvs]

Re: How to Fix your Vizio M470NV and M550NV

Jimmypooh

Per the original post,

"The Q29 transistor is located about 2 millimeters off to the right of the large heatsink. It is a very small three legged surface mount component."

I have attached a picture to display the exact location of the component.
Remember you must replace the Silicon image as well as the transistor located at location Q29

[Jimmypooh]

Re: How to Fix your Vizio M470NV and M550NV

Sorry for the confusion. I was able to find it, I mean what transistor is that? i.e. where can I order one? Mine tested out with the specs you mentioned but your instructions suggest to replace anyway.

I'm going to give this a shot for some fun, but if I can't seem to get it working I'm planning on sending it your way if you're still doing these repairs.

Thanks so much for the help. Let me know if there is anywhere I can donate to give you a tip for your help!

[Nick's Tvs]

Re: How to Fix your Vizio M470NV and M550NV

Jimmypooh,

Unfortunately, this is not a question I will be able to answer for you. We have had issues in the past with suppliers running out of stock on certain parts, and having to work very hard to find alternative ways of getting parts. Due to this, as a rule of thumb, we don't give away our sources anymore unless parts are plentiful from many sellers.

What I can suggest however is to have you just replace the silicon image and boot up the set. If the transistor is indeed faulty or has some sort of damage, you may see issues with the audio malfunctioning, or other various small problems, with boot up. You will not see any additional damage however from booting it up with a faulty transistor, especially if you are getting proper readings on it. I would suggest however testing it for an extended period of time before buttoning everything back up to ensure everything does indeed work properly.

[Jimmypooh]

Re: How to Fix your Vizio M470NV and M550NV

No worries. Thanks for your help. Expect me to reach out when I get it fix or when I fail and need to send it to you .

[Jamescbarrow]

Re: How to Fix your Vizio M470NV and M550NV

Hey Nick I have a Vizio M470NV, It has the symptoms of a main board failure, it will not power on, before it quit the hdmi ports had not worked in months, I checked the voltages on the power supply at it only had 5 volts on one of the 5 volt rails. am I correct in thinking this is a main board failure.

[Nick's Tvs]

Re: How to Fix your Vizio M470NV and M550NV

You could have a T-con issue as well. No picture on screen, but LED's lighting up generally means data is not sent from the main board to the T-con, or the T-con is not sending the information to the screen. In this scenario, since you have stated you already had issues with HDMI ports on the main board, no matter what your main board is faulty and needs to be serviced. There is a 75% chance this will also take care of the no picture issue. However there is of course a 25% chance this no picture issue is being caused by the T-con board as well.
This is a tricky diagnostic with a simple solution however. Since your main board has started to fail some time ago, regardless of the situation, you will want to service it, or it will stop turning the TV on all together very soon. Once that module is serviced, it will be very easy to determine if the T-con is also at fault or if the main board repair took care of all the symptoms.
Hope this helped

[Jamescbarrow]

Re: How to Fix your Vizio M470NV and M550NV

Thank you for your help, yeah we was just sitting here using the tv, and it went off will not do nothing, other than a dimly lit vizio image at the bottom, let me discuss it with the wife, and I will be giving you a phone call, you are in AZ right.

[Nick's Tvs]

Re: How to Fix your Vizio M470NV and M550NV

That is correct

[Jamescbarrow]

Re: How to Fix your Vizio M470NV and M550NV

Nick I wanted to ask what kind of turn around time do you have on getting a board serviced, also wanted to ask, the tv had a intermitten issue with the screen color showing a red tint on the display, could this been because of a main board going bad, or could it of been interference from a nearby router, as it was close by, and the tv did not start doing that till I had internet installed.