Vizio M50-C1 will not power on

[nomoresonys]

Re: Vizio M50-C1 will not power on

Start with the outer most cap, test them in ohm mode, what do you get? You mean the little MLCC caps on the driver board between tcon and panel show short right? I expect those to read over 100 ohms with meter set to 200 range.

[sangeet101]

Re: Vizio M50-C1 will not power on

Thanks I will give it a try in the evening...I will let you know

[sangeet101]

Re: Vizio M50-C1 will not power on

well ! I checked all the caps, no short on them... shows registance higher than 100 ohms. I see the short on the board. caps legs where they sit shows short. one of the cof ic gets hot.. could that be short coming from glass LCD ?? seems like it COF IC short. please help

[Nick's Tvs]

Re: Vizio M50-C1 will not power on

In response to voids_warranties previous post, sorry this is a late response but no one addressed the question so I will in case this happens to someone else.

If the original main board had the following symptoms:

When plugging in the TV to power the white standby light at the bottom corner of the TV illuminates for 4-7 seconds then fades away. Then once it fades you can press the power button and see the light come back on, but have no picture, no backlight, no audio, checking the screen with a flashlight yields no picture.
That is a classic main board failure we see often.

The replacement you mentioned caused 20 blinks to occur. if that is the case, then new main board is defective simply in a different way.

Also warning to everyone with this TV, or similar model with similar main board. The eeprom will almost never fix your issues. Save your money!

Now to address every other potential question and the only thing needed to trouble shoot the board.
Take hot air and heat up that large black heat-sink on the main board. This is a large heat-sink, has 2 BGA chips under it, and will require a lot more heat than a normal small heat-sink. Generally with our hot air gun we will heat up each chip for about 20 seconds each, then let the heat soak into the board for 20 seconds or so, and then heat up the heat sink for an additional 20 seconds for a grand total a 1 minute of hot air to that heat-sink.
Plug the set to power, wait the 5 or so seconds for the white light to fade, then press power and you should have full picture on screen and back to full functionality until the heat-sink cools back down. If it doesn't work the first time around, wait a minute or so and repeat the heating process a second time.
This should also resolve the half screen works other half doesn't.
The p552ui-b2 Vizio main boards also cause a half and half screen issue which can be temporarily solved by heating up the heat-sinks in a similar manner.

I hope this post helps answer a lot of future questions.

[nickgronk]

Re: Vizio M50-C1 will not power on

In response to voids_warranties previous post, sorry this is a late response but no one addressed the question so I will in case this happens to someone else.
...

any idea why the left half of this Vizio M50-C1 tv fades and goes grey? TV works for a few minutes then left side goes wonky. Right side is perfect.

[Storyteller12]

Re: Vizio M50-C1 will not power on

Mainboard is bad. That’s a symptom of the BGA chips going out.

This model is famous for the mainboard failing

[DXseekerMO]

Re: Vizio M50-C1 will not power on

For those who run across this thread, applying heat to the black heat sink on the Main Board can be an easy way to diagnose a BGA solder issue at the processor. Heat it to no more than 325 degrees, let it sit for 30 seconds then try to power on the TV. If it turns on, the Main Board is bad. This diagnostic method works about 60% of the time. If you have a BGA re-work station you may be able to re-ball the processor.

I've found when the 12V line on the Power Supply has 19V and there's no power to the T-CON the Main Board is bad. Test for voltage at the T-CON test point marked VIN.

If the complaint is the TV turns on w/backlights and no picture and the VIN fuse and voltage to the T-CON are good then the panel probably has a short on the screen. In these cases I isolate the side of the screen that is shorted by detaching one FFC from the bottom of the T-Con at a time and turn the TV on to see if a picture returns on one side. Whichever side does not show a picture I apply the scotch tape cut-off method to the 4 outboard traces of that FFC and often times the picture returns.

If the complaint is the TV turns on w/backlights and no picture but the screen has some pixels illuminated on one corner then the screen is likely shorted. When I apply scotch tape to the 4 outboard traces of the FFC on the side the pixels appear often times the picture will return.

It may be necessary to cover more than 4 traces for the short to be bypassed. I've gotten away with covering only 2 traces. It just depends on how bad the screen is shorted. Searching the site here for "tape cut-off" will yield lots of results and how to do that.

This particular style of Main Board (has the same heat sink on the Main Board, found in multiple models) is known for BGA solder failure and for failing with the symptom of 19V on the 12V line.

I'm pretty fortunate to have 4 of these M50-C1 Main Boards that are good. Now all I need are some TVs to put them in!

[nickgronk]

Re: Vizio M50-C1 will not power on

Mainboard is bad. That's a symptom of the BGA chips going out. This model is famous for the mainboard failing

Yep, after reading through these threads looks like I need to find a new board. Super odd though. The tv works perfectly for a few minutes, then the left side goes out, turns pink with a sh|t ton of lines. Then sometimes comes back, then pink lines. Also noticed the remote stopped working as soon as the left side went wonky. Posting some pics.

Would anyone consider a reflow? Does it work? Bunch of ppl on FB marketplace giving away toaster ovens...

[nomoresonys]

Re: Vizio M50-C1 will not power on

Thanks DXseekerMO, that's a lot of great info. in just a few paragraphs.

[diif]

Re: Vizio M50-C1 will not power on

Would anyone consider a reflow? Does it work? Bunch of ppl on FB marketplace giving away toaster ovens...

Yes, you have nothing to lose, add flux.

[nickgronk]

Re: Vizio M50-C1 will not power on

lol. I attempted the EZ-Bake oven method. Did not work. Ordered another board from tvpartstoday for $45.