4K Vizio TV M70-C3 How To Diagnose

4K VIZIO TV M70-C3 full diagnostic guide
Are your symptom not covered? Leave us a comment!

This video shows how to diagnose the following model TVs
M60-C1, M70-C1, M80-C1, P602ui-B2, P702ui-B2, D58U-D3

Send us your power supply for repair:

Send us your mainboard for repair:

[phone]

[cup_and_cone]

Here's an interesting one for you: When first plugged in, the standby light flashes several times and then fades out. When the power button is pressed the standby light turns on for a second and then fades out. No visual damage to any board. I probed the power supply connector and I get 3 volts on the "PS-ON" pin when I hit the power button. When I hit the power button again the 3 volts drops to 0... This leads me to believe it's the power board as the mainboard is correctly commanding power on and off with the power button. However, I am getting 13 volts from all "+13VS" pins, even with the power supply presumably commanded off by the PS-ON remote wire de-energizing. I am getting zero power from any of the "LED-OUT" pins. Do you know what "VSNS" means on the power supply connector?

I agree caps are good to check, but modern powerboards have so much filtering they don't have as many as they used to.

[JonathanDavis-vn]

Thank you for the video. Any advice on places other than ebay to get a new mainboard?

[UnderYourMother]

thanks for a concise to the point video. No fluff and helped me diagnose my problem.

[anthonyg]

Good video. I seem to have both issues sometimes it will not power on even with the illuminated indicator light. When it does turn on I have black patches everywhere and the TV is quite dim. Sometimes the LED strip will flicker at the lower left of my screen. I also have a m60-c3. What do you recommend? I don't mind tinkering since the TV was free but I really don't want to put a ton of $$ into it.

[marklyman]

Hi Nick - my TV showed half the screen as static, then shortly after it went dark, but I could hear sound. I tried the flashlight test (many times) but could not see any image. Any advice would be greatly appreciated. Thank you!

[adamhonse]

I'm trying to diagnose my issue, powerlight comes on, Powersupply voltage on is 5V. Looked at the caps, and they look good. Measured voltages at the power supply, and all the T-conn voltages are 0, but everything else is within spec (?). 12v -12.69, 24v-33.2 (to LED driver), only T-cons are 0. I think those 0Vs are coming back from Main board.

[uptonverley]

Hi Nick I have a Vizio tv model E70-D3 and the problem I am having is that the tv powers on and I have a picture on the screen but there a few horizontal lines and vertical lines on the screen along with a few thin dark spots and a more like oval shape dark spot. Can you say what could be the problem?

[diegoforte]

Hey Nick, I replaced my power board because it had the same issues like you showed with the capacaters. But the now the issue is that the tv will turn on, but now show anything. The screen barely lights up. Would it be a mother board issue then?

[mattk]

Hi Nick, standby LED comes on and unit seems to power on, but no picture/backlight/sound Negligible voltage (0.001-0.003V) at T CON_ON and both 12V T CON pins. 12V on both +12VS pins. 33.xxV on 24V1 pins. No visible bad caps on psu. Possible lightning surge. Main board? Cost to replace? Thanks

[niecylee]

Smart LED LCD TV M70-C3, i replaced all boards and power supply, comes on has light ect . the remote does not do any input even with new button board, could the ribbon be bad or kinked ? thanks

[pjlopez]

Hello Nick, question and looking for some guidance . Channged out 1000uf set of 7 got voltage coming through all with exception of c214 location and have good voltages on pins except for pins 13, 14 t-con 12volt any thoughts? thanks in advance for pointing me in right direction. Boston, Mass. 04/22/2023

[Aktzin]

Can you help me narrow in the issue I'm having. I have a M60-C3 and when I press the power button it lights up, but fades away. No picture. Optical red light is on. Then if I press it again, it lights up solid, then blinks indefinitely then stop which I'm guessing is it shutting off from idle. The red light is on the main board lit up as well.

[DK-bkvq]

Hey Nick, I have a good one for you...
I have a new Vizio 43" FD TV, and a broken screen Vizio 43" UD TV.
Do you think, in your professional opinion, that I can install the new TV screen into the UD Vizio? The interior electronics will remain the same as I'm only switching out the screen and the connector. What say you, oh exaulted one?

[tmho]

I have the M60-C3 (I guess the same series but 60" version). There is a vertical blue line on the right side starting from the top to about 3/4 of the screen height. It is very obvious when the screen is dark and it cannot be seen when the screen is bright. Could you please kindly advise what would be the cause and fixing method?

[miltonreid]

I need a main-Board for purchase same model Tv. Thanks in advance

[GARY-fromOntario]

I have a M70-c3 that wil intermittently turn on. Most of the time the remote will not turn on tv but stand by light will come on then go out. Sometimes using the power button on the back it will turn tv on. Usually end up unplugging, plug in and then turn on from back of tv., ( still sometimes may need to do this a few times to get the tv to power on with picture. ONCE the tv is ON then I can REPEATEDLY use the remote to turn tv on and off and it works. But if let sitting the same issue all over again. My QUESTION is the CAPACITORS the problem?

[combofishing]

Hello i have a M60-c3 the white light in the córner is on but the screen does not turn on.

[WhenKittensATK]

My TV turns on with no video. Holding a flash light to it doesn’t show a picture so issue seems to be more than a backlight issue. Sound will play for maybe a minute and then stop. TV might be turning itself off hard to tell. Seems like it might be a lot cause.

[niecylee]

replaced ir sensor and remote has power n light, ir still does not turn on, could it be the cable ? or maybe they sent bad sensor ? thanks

[williamtorres]

what about the back light problem ? My m70 turns on, led light turns on, splash the V logo and then goes black, i can flash a light and see picture in the back ground. How do you fix that problem? TIA