VIZIO M70-C3 No Power/Power Board Help

[jwelch5792]

Hello,
I have a Vizio M70-C3 that will not power on. After a little bit of research, I found out that I have 4 bad capacitors on the power board. While I was looking over the board to found the bad capacitors I also found a pin next to the 4 bad capacitors on the board was not soldered on the board correctly from the factory and wondering if I should repair it when I replace the capacitors. I am thinking that maybe I should not repair it because have been that for years and the tv worked fine with it not being soldered. I have attached some photos to show what I am talking about.
Thanks for the help

[nomoresonys]

Re: VIZIO M70-C3 No Power/Power Board Help

That pin is soldered in place on the other boards I have looked at, do you know the history of the tv? can you tell if that D201 has been replaced or re-soldered? Fixing that and those 4 caps might be all you need.

[jwelch5792]

Re: VIZIO M70-C3 No Power/Power Board Help

The TV has never been repaired this is the first time the TV has ever been opened. I have had this TV for years and I bought it new. Why I am questioning if it need to be fix it the fact that it has been that why from the factory,

[R_J]

Re: VIZIO M70-C3 No Power/Power Board Help

That is a dual diode and it looks like it missed the hole from the factory, I would insert the diode leg in the hole and solder it in place. The tv did work with only one of the dual diodes in place but it should have both, the diodes will be in parallel

[MichaelInOr]

Re: VIZIO M70-C3 No Power/Power Board Help

I have the same TV, a M70-C3 and the same 4 capacitors are bad on my power supply board. They are bulging. What is the value of these capacitors? uF and voltage? Is it worth to replace them with bigger capacitors?

My capacitors are strategically glued down to hide the values. I popped two of them off the power supply board and plastic wrap around the capacitors are strategically stuck to the glue so they can not be read.

Thank you for the help!

[MichaelInOr]

Re: VIZIO M70-C3 No Power/Power Board Help

i have the same tv, a m70-c3 and the same 4 capacitors are bad on my power supply board. They are bulging. What is the value of these capacitors? Uf and voltage? Is it worth to replace them with bigger capacitors?

My capacitors are strategically glued down to hide the values. I popped two of them off the power supply board and plastic wrap around the capacitors are strategically stuck to the glue so they can not be read.

Thank you for the help!

[MichaelInOr]

Re: VIZIO M70-C3 No Power/Power Board Help

After some very careful prying it looks like I have the correct values:


1000uF 16v

I ordered the following expensive high-end capacitors as replacements. 1000uF 25v and 20000 Hrs life expectancy @ 105°C. These caps are a little taller but the same diameter as the originals. The board looks to have plenty of room for the extra length. I ordered a package of 10 from DigiKey. It was only a couple bucks more than ordering 4 capacitors. $25.31 with 3 day shipping. I could have gotten cheaper but then I would be just as cheap as Vizio was originally. I believe that I shouldn't ever have to do this repair again and hopefully this Visio will last as long as a Samsung TV now.

Digi-Key Part Number
493-11281-ND
Manufacturer
Nichicon
Manufacturer Product Number
UPX1E102MHD
Description
CAP ALUM 1000UF 20% 25V RADIAL
Detailed Description
1000 uF 25 V Aluminum Electrolytic Capacitors Radial, Can - 20000 Hrs @ 105°C

https://www.digikey.com/en/products/...102MHD/4319346

[MichaelInOr]

Re: VIZIO M70-C3 No Power/Power Board Help

New Nichicon capacitors are in:

Not EXACTLY an exact match for size.


I used some wick to suck out the old solder. Soldering the new ones in was easy enough.


I little tighter fit.


I put in a good bed of silicone.


Even though they look tight it would be very hard to short out the leads and the silicone is doing a good job of keeping the new capacitors separated off of the surrounding components. This pic makes the leads on the far left cap look really close together. They actually have a good amount of distance between them.


The set fired right up!

The hardest part was removing the TV from the wall mount then putting it back up once I was done. On the last TV I repaired (helped repair) my father took me down to the drug store and he taught me how to check the tubes to see if they were good or not.

In the realm of things I would say this is a pretty easy repair. Moving the TV around is definitely the most difficult part. If you could get some help moving the TV is would be considerably easier.

[dskall]

Re: VIZIO M70-C3 No Power/Power Board Help

I still remember my dad and I would make our semi-annual trek to Thrifty to check our tubes. Good times.

[armandoca]

Re: VIZIO M70-C3 No Power/Power Board Help

I replace all the caps on my tv and check for voltage - all caps give a reading except for one C214. am I missing something?

[nomoresonys]

Re: VIZIO M70-C3 No Power/Power Board Help

resolder it, sometimes it doesn't take right.

[R_J]

Re: VIZIO M70-C3 No Power/Power Board Help

I replace all the caps on my tv and check for voltage - all caps give a reading except for one C214. am I missing something?

C214 is for the T-con +12v, You are likely missing the t-con_on signal from the main board.

[armandoca]

Re: VIZIO M70-C3 No Power/Power Board Help

resolder and replaced the cap. still no voltage

I had a feeling C214 could be waiting for a single from the main board, how can I check for this single?

by the way there is a red light that turns on - on the main board when I press the power button.

[armandoca]

Re: VIZIO M70-C3 No Power/Power Board Help

forgot to mention the power light flashed 16x -

[R_J]

Re: VIZIO M70-C3 No Power/Power Board Help

Check the voltage on the t-con_on pin, monitor this pin while turning on the tv to see if it changes.

[armandoca]

Re: VIZIO M70-C3 No Power/Power Board Help

t-con_on fluctuate from 0.00 to 0.01 while turning on the tv

[nomoresonys]

Re: VIZIO M70-C3 No Power/Power Board Help

yep, looks like no tcon on signal from mainboard as mentioned, should probably be 3.3 volts or so, looking like mainboard issue.

[nomoresonys]

Re: VIZIO M70-C3 No Power/Power Board Help

There's Nick's doing a pro reflow, that's probably what you need, I do believe he gives a warranty too: https://www.youtube.com/watch?v=IkFCE42zoLM

[dskall]

Re: VIZIO M70-C3 No Power/Power Board Help

Try pushing on processor while pressing the power button. Or heating processor and trying to turn it on.