Vizio M60-C3 won't turn on. Is it the main board?

[afdreher]

Hi, I've been stalking the site trying to diagnose the problem with my Vizio M60-C3. When turned on, the screen remains black and there is no audio. There is nothing displayed on the screen using the flashlight test, but the status light does illuminate and the optical audio out port does illuminate. The symptoms are almost identical to https://www.badcaps.net/forum/showthread.php?t=51443.

On the power supply board (60CAP090), with the TV off, everything reads ~0V except for the two +12V rails (pins 8 & 9 on the connector the main board (CN201)), which read 12.57V, and the AC-DET (pin 12), which reads 3.79V.

When I press the on switch, the status light illuminates and then starts to flash, indicating some kind of problem.

On the connector to the LED driver board (CN301) top right connector on the power supply board), the X00020 pins (pins 3-8) read 26.48V, and the pin labeled VSNS changes from 0V to 2.45V. Pin 12 stays at 0V. So the power supply is providing 24V power to the drivers.

On the connector to the main board (CN201), the T CON ON (pin 15) and 12V T CON (pin 14) both remain at 0. Likewise, the power supply provides 0V to the T CON board through pins 1-4 on the connector at the top left (CN202). The 12V rails (pins 8 & 9) remain ~12.55V. The 12V-AU (pin 4) gets activated to 12.55V, although no audio is produced. The PS-ON (pin 3) signal is provided from the main board at 5.12V, and the AC-DET (pin 2) stays at 3.77V.

On the LED driver board, the power feeds in at 26V through CN102. All of the pins for the CN101, which I believe from reading through the other posts is the BL-ON signal, read 0V.

There aren't any obviously blown connections, FETs, or capacitors on any of the boards.

I'm guessing this is a main board problem because there isn't a signal telling the T CON and BL to activate. Am I correct? Is there something else I should check before I try to hunt down a new main?

Thanks so much!

[neilc6]

Re: Vizio M60-C3 won't turn on. Is it the main board?

Most likely bad bga connections on the processor of the main board. Symptom is ON/OFF or BL_ON pin not going high (>2.5V) when the tv is turned on. A few threads if you search your model or M43-C1

[afdreher]

Re: Vizio M60-C3 won't turn on. Is it the main board?

Thanks, I'll have a look for those. Most of the previous threads didn't make a whole lot of sense to me principally because Vizio's boards are rather poorly labeled.

[budwich]

Re: Vizio M60-C3 won't turn on. Is it the main board?

what does this mean... "There aren't any obviously blown connections, FETs, or capacitors on any of the boards"... you checked all of the fets with a meter or you used your eyes as "visual confirmation". check for shorts on those especially at the 12v output to the tcon.

[afdreher]

Re: Vizio M60-C3 won't turn on. Is it the main board?

I just did a visual confirmation of the PS board looking for obvious problems.

For anyone else with similar problems, neilc6 nailed it: the main logic board was bad. I replaced that board, and now everything works as expected.

Thanks for all the help!

[jptferreira]

Re: Vizio M60-C3 won't turn on. Is it the main board?

Mine is not reading correct voltages at the power supply but has the same exact symptoms. I'm reading 19V where it should be 12V at the PS board, is this normal on this system? Do you think it is a PS issue or mainboard?
When I power it on the first time the power led fades slowly, pressing a second time it blinks 15 times. Can't find any vizio support regarding the blink codes. Thanks for any input!

[jptferreira]

Re: Vizio M60-C3 won't turn on. Is it the main board?

It was mentioned to replace the U202 eeprom but I'm not sure it will help with this issue because I believe this eeprom is only in case there is audio and no picture

[neilc6]

Re: Vizio M60-C3 won't turn on. Is it the main board?

Vizios don't have blink codes. 19V is ok. Check for BL-ON not going high. You can also heat up the processor with a hair dryer to confirm before plugging in.

https://www.badcaps.net/forum/showthread.php?t=76708

[DemonBG]

Re: Vizio M60-C3 won't turn on. Is it the main board?

For what it is worth, i had exactly the same issue on a M60-C3 i picked up cheap.

Symptom: standby light comes on, then fades out + optical port lights up. No backlight, no sound. after a few moments the standby light goes off and after pressing power again, the standby light flashes 16 times without powering on.

Assessment: Verified PSU was providing 12v and 5V (PSon) but was not delivering 5v to the LED board.

Diagnosis - Bad BGA contacts under the chips on the main board. my paricular set showed some heat discoloration on the heat pipe and also around the heatsink itself so clearly this thing had gotten HOT.

Repair - I attempted a repair using a heat gun reflow (Without flux) and it got the TV working for about 20 minutes - At least long enough to verify the problem. I am going to try reflowing it again with flux and a IR temp gun to verify i get the solder molten before buying another board (They cost $100+ at the moment). either way i will probably wire in a 12v fan to run on the heatsink to keep temps down going forward.

Thanks for the support all.

[neilc6]

Re: Vizio M60-C3 won't turn on. Is it the main board?

https://www.badcaps.net/forum/showthread.php?t=76708

[econjon]

Re: Vizio M60-C3 won't turn on. Is it the main board?

I am in the same boat as afdreher was. Testing exactly as he described. I am a novice so not up to reflow (toaster oven) the existing board. Just want to check that the read on cn101 should be >0 when tv is powered. Found a replacement board for $80 so worth a shot

[econjon]

Re: Vizio M60-C3 won't turn on. Is it the main board?

Just a bump...question. I baked the main board and the tv now turns on but left half flickering. Anyone else get that/possible solution? Thanks

[ossroy]

Re: Vizio M60-C3 won't turn on. Is it the main board?

Initially, I had an issue last winter where, when the room was cold, the TV came on but continuosly scrolled through the inputs. Slapping the back of the lower left where the button board and light are would solve things until the room warmed up and things worked fine.

Then it started coming "on" but no picture, just backlight. Turning it off and on again fixed things. Then it got worse, where I'd have to cycle power several times to get picture. Then I got the dimming light and sometimes flashing after dimming. Again, cycle power a few times and it would eventually work fine.

Now it is dead. I took off the back and started measuring. The only low voltage I get is about 3.3v and 2.something on a few pins. But those voltages make it to the button/IR board, so I'm guessing that's the stand-by voltage and my measurements may be normal for a unit that is off. Not sure where to go from here. I'd like to hope it's the PS because it's probably cheaper than a MB. I saw one YouTube video where the guy just replaced the 4 identical caps at upper-right on PS and fixed it. Based on all those progressing symptoms, any thoughts?

Roy

[Nick's Tvs]

Re: Vizio M60-C3 won't turn on. Is it the main board?

If one side of the screen is not displaying correctly is still the mainboard. You have 2 BGA chips under the heatsink. I recommend you reflow both, if you still have issues you may have to replace or re-ball one of the chips.
I have a video on the repair of that exact problem. It's not always a replacement, sometimes you can get away with reflow or re-ball so if it doesn't work you may not have reflowed the board properly and I would suggest you try again.

https://youtu.be/G1Rh6Snf94g

[Pooshoes]

Re: Vizio M60-C3 won't turn on. Is it the main board?

Visio's certainly have issues with the BGA chips, I figure the solder they use grows tin whiskers. Reflow the chip and once it's working turn off "quick start" and the processor won't run hot 100% of the time, just takes longer to boot the panel.