On Thursday, November 19, 2020 at 11:07:18 AM UTC-5, Chuck wrote:
On Wed, 18 Nov 2020 14:53:23 -0800 (PST), Hilda Winkler
wrote:

On Thursday, November 12, 2020 at 6:35:04 PM UTC-5, wrote:
On Thursday, November 12, 2020 at 4:52:39 PM UTC-5, wrote:
On Friday, November 6, 2020 at 9:10:58 PM UTC-5, Hilda Winkler wrote:
On Friday, November 6, 2020 at 9:54:50 AM UTC-5, wrote:
On Thursday, November 5, 2020 at 6:31:05 PM UTC-5, Hilda Winkler wrote:
On Tuesday, November 3, 2020 at 4:37:19 PM UTC-5, wrote:
On Tuesday, November 3, 2020 at 3:50:05 PM UTC-5, Hilda Winkler wrote:
Hi Group, can someone help please. I have a VIZIO Model # M550SV 55" randomly shuts off/on.. I checked the voltages on power supply board all are correct.. after doing research online, there seems to be a firmware problem. i hooked up to their website, couldn't find any updates.. is there a fix to this TV, ???
That series is known for bad main boards that show all sorts of symptoms. No new ones are available, and used ones may put you in the same boat in a few months. Even when Vizio sells them, they are "recertified", which means they tested them to see if they work for 5 minutes and box them for sale. We've reflowed the BGA chip with inconsistent results but no longer take those in for service.

That TV can update its firmware when connected on-line, but it doesn't seem Vizio ever released a later version of the firmware it was shipped with.

is there a board number locater for this BGA chip, ??? I have a hot air soldering gun, im gonna try to reflow it. would 350 degree's for 2-3 minutes suffice???
It's the one under the silver heatsink. Remove the heatsink carefully because the sink will be stuck to the BGA. If you rip the BGA off the board, it's junk.

We've tried several profiles but they're hit or miss. Ideally it should be reballed or the chip outright replaced. Because of the drop in price for a new TV, we've stopped servicing this model.

I would go less on the temp, maybe 325C for 3 minutes tops. If it works, considering opening a hole in the back cover and adding a slow moving fan.
after taking the over off, and visually inspecting the boards. I found five bulging caps 220uf, 25v all the same. on the main board. ordered new ones, will post if successful..
I replace the bad caps, not successful, still got the vizio logo frozen on screen, then i tried to heat up the BGA chip, now the set is dead..??? no logo, no back lights.
Reflowing is a bit of an art. You need to get the chip hot enough to reflow the crappy lead free solder that is brittle and flows at a higher temperature than tin/lead that they use these days, but that much heat is close to where the chip dies... temperature over time. You also need to be sure you don't warp the board under the chip while you're doing this.

*BUT*(!), you said in your first post you were getting a random shutoff condition, and now you said it was getting stuck on the Vizio logo on the screen. That's a different issue altogether, although it's probably too late now because you might have torched the BGA.

The M550SV not starting at all or getting stuck on the boot logo is generally a corrupted NAND chip on the back side of the board. It's a 48 pin surface mount TSOP1 flash (the only one on that board) and isn't easy to change if you don't have surface mount soldering experience. I used to change them when the TVs were pretty new until the BGAs started acting up as the TVs got older and built up miles.

Check your connections. If you can get it back to the stuck logo, you can order one of these already programmed from a guy in Texas - I think it's Coppell TV or something close, and change it if you can solder tight pitch smd stuff. If not, keep trolling ebay for a cheap one.


after reheating the BGA chip, i checked the power supply board. and I'm getting zero volts going to the main board on all pins. looks like a short, checked all connections. maybe i could have melted the solder under the chip when reheating and created a short???


Very possible. That is what happened when I reflowed a bga chip on my
son's X-Box.


I did look for shorts, didn't find any. i do get 5v stanby. I get 5v on fuse one on main board nothing on fuse two, and no voltage on ce2 and ce2 caps, these are two of the five bulging caps that i replaced... i get 5v on voltage regulator main board