Vizio M43-C1 - How closely do I need to match the mainboard number?

[Devonavar]

I have a Vizio M43-C1 stuck in a reboot loop with no backlight.

I've tested all the voltage rails coming out of the power supply and they are "normal" for this model (PS_ON & DIM go high when turned on, BL_ON & 3D_ON are close to zero due to backlight power flowing through the mainboard, 5VSB is 5V, and 12V is 19V, which is apparently normal for this board).

Basically, I get similar results to Garry in this post: https://www.badcaps.net/forum/showthread.php?t=80346

So, I've ruled out the PSU for now.

The reboot loop sounds pretty similar to this thread: https://www.badcaps.net/forum/showthread.php?p=1156275 . Basically, the front LED lights up bright and then fades down as usual, and then ~90 seconds later, it lights up bright again in a cycle. With so many other people reporting mainboard failures on this model due to overheating, I'm thinking mainboard failure is the likely cause.

So ... what to do about it? I'd like to just order a new mainboard, but I can't find an exact match that is in stock, which makes me think I probably won't find one on a TV released in 2015.

I've identified two different board numbers, and I'm trying to figure out how closely they need to match.

There is a barcoded sticker that reads: (Q)XFCB0QK003040Q 1536

And there is a board number etched onto the board itself: 715G7288-M02-000-005T

I've managed to find a board that's in stock that matches the second number but not the first: https://www.tvpartstoday.com/756TXFC...fcb0qk0120.htm

I'm guessing here, but would it be reasonable to assume that this is the correct piece of hardware (the number etched onto the PCB) with the wrong software / firmware (the number on the sticker)?

The model number for this board is identified as M50-C1, which is just a larger version of my TV.

So ... if I purchased this board and installed it in my TV, would it work? I'm hopeful that it would based on this this post: https://www.badcaps.net/forum/showpost.php?p=1132740 , where a user reported success installing a mainboard for a D50u-D1 in this model (though, he didn't identify the board number of the board he replaced).

What would be the ramifications? I end up with a 43" TV that thinks it's 50"? Would this matter in any material way? Could I re-flash the firmware to the correct model? I'm assuming most of the relevant differences in the LCD logic, not the mainboard. Is this worth trying?

[Devonavar]

Re: Vizio M43-C1 - How closely do I need to match the mainboard number?

Option 2: If buying a mis-matched mainboard is a bad idea, I've found an eBay vendor that repairs this model of mainboard. https://www.ebay.com/itm/11483653602...cAAOSwOJ1gneEy It's a bit more expensive than option 1, but it comes recommended by someone else on this forum (shout out to @Neilc6!)

I guess what I'm wondering is whether I can trust a random eBay vendor to do a real repair (presumably, a reflow / re-solder of the BGA that is beyond my amateur abilities) and not just do a toaster-over repair that will fail in weeks or months? Does anyone here have experience with this vendor (and maybe Neilc6 could chime in if he sees this)?

[handsworth]

Re: Vizio M43-C1 - How closely do I need to match the mainboard number?

This guy has done 2 of the M50-C1 boards for me this year. No problems, fast turnaround.

[nomoresonys]

Re: Vizio M43-C1 - How closely do I need to match the mainboard number?

good option If they give a decent warranty.