ViZIO M70-D3 Completely Dead (Weird!)

[goofykao@yahoo.com]

Hi, Just joined this forum hoping to fix this TV.

Sorry for the long post to explain the problem in details.

Model: VIZIO M70-D3, 4 years old

What happened: TV had no issue at all and one day just died (4 weeks ago) and NO LED stand-by light (usually it's Red at bottom left front side)

Current status: Cannot power on and NO LED stand-by light

Strategy: Since I am not good at fixing boards at component level, it's better for me to just replace boards with known good ones

Trouble Shooting History:

1. Ensured the power connection was good and full battery in the remote control
2. Followed all possible procedures to power-cycle the TV
3. Purchased identical Power Supply, Main, T-Con boards from TVPartsToday and tried all possible combinations between old and new ones
4. Kept logs of voltage measurement while swapping boards and all readings are the same, e.g., old and new boards behaved the same way
5. While performing all these trouble-shooting, TV power and stand-by LED has never been ON (dead all the time)
6. Used magnifying glass to visually inspect old and new boards and found no difference (at least appearance are identical and no indication of damage)

Voltage measurement data (values are identical between old and new boards):

1. Power board (09-70CAR0C0-00): Both old and new ones behaved the same.

Isolated:
-AC-DET: 4.36V
-PS-ON: ~0
-16VS: 16.2V

Connected to main board:
-AC-DET: 3.95V
-PS-ON: ~0
-16VS: 16.2V

PS-ON no change while pressing remote or power-on button

2. Main board (Y8387242S): Both old and new ones behaved the same.

-USB port has 5V but it won't charge an iPhone (used it to test the power)
-There is 3.2V to the stand-by LED but LED is not lit
-Optical port has NO light while trying all old and new board combination

3. T-Con board (RUNTK0151FVZZ): Both old and new ones behaved the same.

-Tried disconnected from main board and attempted to power on TV but not working

Possible explanation: The new ones from TVPartsToday are also BAD (in the same way). But what are the odds??

Any help is appreciated!! Thanks.

[R_J]

Re: ViZIO M70-D3 Completely Dead (Weird!)

If you tried the Power supply, main and T-con, that leaves the panel itself, try disconnecting the panel from the T-con and see if the TV turns on.

[goofykao@yahoo.com]

Re: ViZIO M70-D3 Completely Dead (Weird!)

Thanks a lot for the help!

I followed your instruction and the TV turned on!!

Please advise what I can do next. Thanks!

[nickgronk]

Re: ViZIO M70-D3 Completely Dead (Weird!)

There should be two ribon cables, 1 on either side of the TCON (left and right side of panel). I suggest unplugging 1 side, trying to turn the set on. Vice versa. If you get a picture on one side, there is a problem with the panel - let us know how you make out. If its only a bad TCON then thats an even simpler fix. Cheers

[carlosemarin]

Re: ViZIO M70-D3 Completely Dead (Weird!)

Did you finally identified what was the problem? I got exactly the same symptoms with my TV. 4 years and boom... dead. Thanks

[frannyjunk]

Re: ViZIO M70-D3 Completely Dead (Weird!)

Did you finally identified what was the problem? I got exactly the same symptoms with my TV. 4 years and boom... dead. Thanks

I have the Vizio M60 C3 which is dead. No power whatsoever. Upon opening the back cover, I noticed 4 bulging capacitors. I will be replacing these capacitors today when the new ones arrive. According to a YouTube post, that should do the trick.