Vizio M320SR turns off after logo

[dick_barton]

Re: Vizio M320SR turns off after logo

There a 80 leds along it's length divided into 2 stings of 40 giving an approximate driving voltage of 40 x3V = 120V per string

[Roush2fast]

Re: Vizio M320SR turns off after logo

How long do the leds stay on for before going off. Can you turn the backlights all the way down so you can see if any one led is not illuminating.

The TV worked again yesterday until I turned it off so they were on for quite a while. When it was functioning I turned the backlight down to 25. I really don't want to reassemble the TV to turn it down to 0. Anyway I am still seeing the LED strips when I close my eyes from confirming all are lighting up and they are doing so equally. I included a picture in my last post that shows they are all on. Right now with the TV in failure they stay on for about 2 seconds. This is getting frustrating. Normally I would just buy a new TV but I have too much time vested into this and I really want to determine what's causing the backlight to shut off and work intermittently.

I guess I can wire up a battery tester and see if I can test each one individually but I'm 99.9 % sure they are all lighting up.

[dick_barton]

Re: Vizio M320SR turns off after logo

When the backlights go "off" do you still have audio and IR control (Volume up and down).

If you do can you measure what voltage you have on the power supply connector for Backlight on.

What is the IC number on IC8512

[Roush2fast]

Re: Vizio M320SR turns off after logo

Yes I still have audio and full menu access just with a flashlight.

Backlight on connector , isn't this the connection I have previous tested ?

IC8512 is fan7529

[dick_barton]

Re: Vizio M320SR turns off after logo

Thanks,
All good so far.
Audio and picture but no backlight.

So need to concentrate on the dropping out backlight only
So is the ON/OFF dropping to 0V. This is supplied from the mainboard.


I'm trying to find what IC is the Led driver and it's not the FAN7529 or the A6069H

What other IC's are on the board to try and locate this driver.

[Roush2fast]

Re: Vizio M320SR turns off after logo

Well have a new problem now. Put the tv back together and I know have a vertical rainbow on the right side of the panel. I was super careful and the process was easy so I have no idea what caused this. Might just be time to purchase a replacement. What could have caused this ?

[dick_barton]

Re: Vizio M320SR turns off after logo

Disconnect the ribbon cable from the tcon going to the panel and re-insert it carefully.
You flip the tab cover lever upwards to release the ribbon from the tcon connector and push it back down when the ribbon is correctly inserted.

[Roush2fast]

Re: Vizio M320SR turns off after logo

Disconnect the ribbon cable from the tcon going to the panel and re-insert it carefully.
You flip the tab cover lever upwards to release the ribbon from the tcon connector and push it back down when the ribbon is correctly inserted.

Ok I will give that a go. thanks

[Roush2fast]

Re: Vizio M320SR turns off after logo

Well it's toast. There's a hairline crack in the corner of the panel. Like I said I was super careful so the only thing I can think happened is maybe one of the panel bracket screws was tightened too much.

Thanks for all your help I learned a lot. If I ever need to service a TV again I definitely feel educated.

Till next time

[dick_barton]

Re: Vizio M320SR turns off after logo

That's really bad luck but nothing that I haven't done myself.

[vinceroger69]

Re: Vizio M320SR turns off after logo

Ive done it too myself on re assembly hence i only do repairs for family/friends and always tell them of the risks involved.