Vizio M70-C3 Dark Spots

[budm]

Re: Vizio M70-C3 Dark Spots

:-) very wise on the "last thing to do" especially as a "first effort". Ultimately, I kind of doubt that to fix this set, there will be an easy / board solution.

I hate to see another broken panel.

[Diah]

Re: Vizio M70-C3 Dark Spots

Hello Diah, I restored the factory defaults and picture still the same. Next, I copied the black and white jpg's to a thumb drive and played them on a slide show for a couple minutes. I could always see the shadows when the white screen played.
Is that the tests you are asking for?
thank you,
Kent

Hard reset meant only the reset which done via Service menu. it roll back all driver and firmware to Factory condition. rest from user menu its just rest the setting of the user.

this test should be done with Cable or areal signal. not USB or HDMI signal.
please turn off the light of your room ( in case the TV set had build in Light room sensor ), and set the backlight level of the TV to Zero. keep it on and watching any things for at least 30 minute. then turn the backlight level setting to up slowly .. but not to full and check the dark spots at which level there no spots.

[kentkirchner]

Re: Vizio M70-C3 Dark Spots

on the specification of the this TV there are full arrow dimming system. as other said. this panel are big the risk to take out with one person do high.

reading voltage don't work at all as its currents to dimming or turn off. if there was one burned then whole back light will be out and TV will never start.
the rest we can think what i said before.. but its much we can know more close with easy steps

1- make hard reset from service menu and check result

2- attached UHD learning full arrow dimming system put them on fat32 usb format and play them on the tv one by one until you can see the white one full White.

if no change please report to do other test

Hello Diah, I restored the factory defaults and picture still the same. Next, I copied the black and white jpg's to a thumb drive and played them on a slide show for a couple minutes. I could always see the shadows when the white screen played.
Is that the tests you are asking for?
thank you,
Kent

[kentkirchner]

Re: Vizio M70-C3 Dark Spots

Sorry Diah, just saw your response above.

[Diah]

Re: Vizio M70-C3 Dark Spots

waiting on your response of the second test i suggest at post 22

[kentkirchner]

Re: Vizio M70-C3 Dark Spots

waiting on your response of the second test i suggest at post 22

OK, turned out the lights in the room and reduced the backlight to zero for 30 minutes. While watching, all dark spots are still noticable . Slowly increased the backlight from zero to 55, checking for spots while doing so and they remain on the screen

[Diah]

Re: Vizio M70-C3 Dark Spots

OK, turned out the lights in the room and reduced the backlight to zero for 30 minutes. While watching, all dark spots are still noticable . Slowly increased the backlight from zero to 55, checking for spots while doing so and they remain on the screen

i do wondering how you can remarkable the dark spots at back light level Zero.. you may have under picture setting some things like Auto Brightness Control.. this need to turn off.

please upload photos as other members request. now start the hard work

[kentkirchner]

Re: Vizio M70-C3 Dark Spots

i do wondering how you can remarkable the dark spots at back light level Zero.. you may have under picture setting some things like Auto Brightness Control.. this need to turn off.

please upload photos as other members request. now start the hard work

Two pics on zero backlight, auto bright off

[Diah]

Re: Vizio M70-C3 Dark Spots

Two pics on zero backlight, auto bright off

do the same test again of backlight level zero.. i thnk this auto brightiness was on... if it was off then no need to do it

i said the test with channel signal not jpeg or s other.. areal signal or cable signal of program that the picture will change and moved time to time

[kentkirchner]

Re: Vizio M70-C3 Dark Spots

It was off, pictured left at calibrated for test, backlight=zero

[kentkirchner]

Re: Vizio M70-C3 Dark Spots

I will be removing the back and taking pictures and posting tomorrow morning

[Diah]

Re: Vizio M70-C3 Dark Spots

It was off, pictured left at calibrated for test, backlight=zero

not good news 4 reasons
1- software issue ( local dimming blocked ) hard reset from service menu can approve it
2-LED driver replacement
3- Led strips ( must all replaced with new one )
4- panel sandwich layers

[Charleyd]

Re: Vizio M70-C3 Dark Spots

Looks like backlights. I had one of these that had gotten hit by lightening. Minor damage to Power Supply that cost $8 to fix, but then 1/3 of the backlights were out. Not fun. A good test video can be found on YouTube by searching for "Monitor Color Test".

[kentkirchner]

Re: Vizio M70-C3 Dark Spots

OK Guys, I have decided to tear it down and look at the LED's. And now for perhaps the dumbest question ever. I would like to plug in and look at the LED's for which ones may be bad. I plugged in, but how do I get them to light up?..sigh...

[jjanssen7]

Re: Vizio M70-C3 Dark Spots

Top tip: make sure that before you attempt to turn it on you have isolated the tconnribbons. I learned the hard way that if you disconnect them from the panel but leave them connected to the tcon they can short against the body of the TV and take out your tcon.

When you attempt to turn it on as normal, they don't turn on?

[kentkirchner]

Re: Vizio M70-C3 Dark Spots

Top tip: make sure that before you attempt to turn it on you have isolated the tconnribbons. I learned the hard way that if you disconnect them from the panel but leave them connected to the tcon they can short against the body of the TV and take out your tcon.

When you attempt to turn it on as normal, they don't turn on?

Great, thank you. no, plug it in and turn on the power but no LED's, but if all the ribbons and IF filter, etc, etc are disconnected , how does it get the signal?

[kentkirchner]

Re: Vizio M70-C3 Dark Spots

OK...sigh...now that everyone, including me has had a good laugh at the rookie. I powered on the set at TV and YES!, I have backlights that are out! Replacing now....wish me luck

[nomoresonys]

Re: Vizio M70-C3 Dark Spots

Take it slow, if unsure watch some youtube vids.

[kentkirchner]

Re: Vizio M70-C3 Dark Spots

just when things were going so well, got the new LED's installed, powered up and all good. I put everything back together and fired it up and no joy, left side of screen was all white and the other side had a picture. So my first thought was the 4 ribbon connectors, so took apart again, re-seated them and put back together. Hung on the wall and fired up again, bottom left corner, screen cracked, wont power up, Game Over! sigh...appreciated all the help guys!

[budwich]

Re: Vizio M70-C3 Dark Spots

guess the dark spots were better than no spots... :-( very disappointing.