VIZIO Model # M550SV 55" randomly shuts off

[Hilda Winkler]

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, ???

[Sjouke Burry]

On 03.11.20 21:49, 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, ???
>

Have you checked for interference (led lights, TL lights, etc),
If they produce interference with your remote control, thats bad.

Old story : a tv with sonic remote control.
Lots of failures,an visits to the shop.

Turned out to be from a parrot, he could hear the sonic control,
and started to imitate the ultra sound.(He hated tv).

[John-Del]

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.

[Hilda Winkler]

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???

[John-Del]

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.

[Hilda Winkler]

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..

[Hilda Winkler]

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.

[ohg...@gmail.com]

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.

[Hilda Winkler]

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???

[ohg...@gmail.com]

On Wednesday, November 18, 2020 at 5:53:26 PM UTC-5, hildawi...@gmail.com wrote:

> > 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???

The power supply when unplugged from the main will output at least one voltage al the time. With just AC applied, check for a standby 5 or 12V (or whatever this uses - could be either). If you see the standby voltage, plug in the main and recheck. If that voltage goes away, something is loading it down on the main. Since the BGA is not powered directly from the power supply, the BGA *shouldn't* be the problem (although who knows for sure?). The BGA is powered from one or more dc buck converters on the main, and those are generally current protected, so if the BGA were to short for instance, the buck converter feeding it would shut down but the rest of the board will have power on it - and I'm speaking generally here on this board. If the standby goes away when you plug in the main, then do a basic dc resistance to ground on the standby line and trace out the short.

If the standby voltage on the power supply stays on when you connect the main, check the ps on command from the main back to the power supply. This should be low when in standby and should go to 2.5 - 5V when the power button is pushed.. If the line goes high, then the rest of the supply should turn on. If the line goes high and only the standby voltage stays on but everything else stays low, check the run lines for dc resistance to ground and trace it out.

You can test the power board on the bench by applying AC and jumping the standby pin to the on command across a resistor. If the standby voltage is 5V, a 270 ohm resistor should be safe. If the standby is 12V, I'd use a resistor and zener to get the voltage down below 5V before applying it to the ps on command line. When you jump the standby to the ps on line, the rest of the voltages should appear if the power supply is good.

If the standby voltage is working but the on command voltage to the power supply stays down when you push the power button, then the BGA could be torched.

[Chuck]

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

[Hilda Winkler]

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

[ohg...@gmail.com]

On Sunday, November 22, 2020 at 12:27:47 PM UTC-5, hildawi...@gmail.com wrote:

> > >
> > >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???

x.
> 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

Did you check for the ps on command from the main back to the power supply?

These things "ping pong". The power supply sends the standby voltage to the main when AC is applied. The main (on command) then sends a logic high back to the power supply to turn on the rest of the supply. The power supply goes into full run and provides the rest of the voltages, including the 12V or 24V back to the main to allow full operation.

All we know right now is that you have the first step: the standby voltage. Push the power button and see if there's any change on the command line back to the power supply. If not, best odds is that the BGA got torched during the reflow.

[Hilda Winkler]

with AC applied. I jumped standby pin to pwr_on pin with a 270 ohm resistor. I got 12v on 3 pins of the power supply. TV did not power on. No voltage going to the backlights.??? so i guess the BGA is fried???

[Lisa Court]

From my chair, yes. Again, BGA reflow is a bit of an art (and maybe some Voodoo as well). I admit I don't have a handle on this either but since replacing BGA chips on TV mains are not economical, so a reflow is get out of jail free card if it works.

No new mains have been available for that series since shortly after the TV was first made, and most of that model have issues with the main board. Since the board has several known issues, a used main board is a crap shoot. You may be back in the same boat in 6 months if you install a used board. I'd troll around ebay and wait for a cheap one that has a guarantee attached. That model is a good performer (local dimming as well), but it had issues for sure.

[Hilda Winkler]

On Friday, November 6, 2020 at 9:54:50 AM UTC-5, ohg...@gmail.com wrote:

what direction is the fan moving, sucking out, or blowing in???

[ohg...@gmail.com]

It doesn't really matter. All you're trying to do is get a bit of air movement over the heatsink, and you'll get that either way as long as the fan is close enough to ensure the exhausted air is moving over the BGA heatsink and not around it. Even a relatively small amount of additional air movement over the heatsink will make a big difference in the operating temp of the BGA.

[Charles Lucas]

On Tuesday, November 3, 2020 at 2:50:05 PM UTC-6, hildawi...@gmail.com 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, ???

One thing I have noticed is that there was a mandate to all manufacturers making new TV's to have
the power supply shut down seconds after there is no signal detection on the system's computer
when not in setup mode, in addition to making the power supplies energy star rated and extremely
efficient (80% or higher). The high cost of energy created this mandate because older TV's were
"power hogs" that ate up hundreds of dollars of cost just to run them monthly.

With that in mind, if there is no signal present on any input after 30 seconds, the set will shut down.
You have to have an actual signal (whether it be analog or digital) there for the set to continue
running. If the computer sees no signal there the system will shut down. You at least need a video
signal there for the set to remain on. Audio is subject to adjustments and mode. Hope this info. helps.
Also, this has been an issue for 14 years, so I educate customers on this.