Vizio XVT3D474SV No Picture, Blinking Logo

[Robb]

Hey all, I got a LED tv with no picture and a blinking logo. It used to occasionally power up. Now the logo just blinks until I unplug it. I have a little experience fixing plasmas but I've never opened up an LED and I can't find a service manual. Can anyone point me in a good direction? I have a DMM, O-scope, ESR meter and soldering station to work with.

Below is a pic of the back panel.

[Robb]

Re: Vizio XVT3D474SV No Picture, Blinking Logo

Hmm, it seems this issue has been discussed and remains unsolved on the 42" model in another thread https://www.badcaps.net/forum/showthread.php?t=23735

That thread appears to contain some useful links for diagnosing LED problems too.

[Robb]

Re: Vizio XVT3D474SV No Picture, Blinking Logo

I think I found the resolution to the other thread https://www.badcaps.net/forum/showth...ght=XVT3D424SV in a separate thread.

The issue was the T-Con board and there didn't appear to be any known way to verify which board was failing as the model is relatively new.

Looks like it's gonna be a gamble.

[Robb]

Re: Vizio XVT3D474SV No Picture, Blinking Logo

Of coarse the T-CON Boards for this model are non existent (Part No. 0171-2372-0079). I guess I'll have to try and find the failed component...the board appears to be getting power.

[ecking767]

Re: Vizio XVT3D474SV No Picture, Blinking Logo

your TV doesn't power ON right? its maybe your main board and not the T-CON board.You can check the fuse and the voltage on your T-con BOARD. And disconnect the t-con board and try to power up your TV. its should power on if the t-con board is cause a problem

[Robb]

Re: Vizio XVT3D474SV No Picture, Blinking Logo

your TV doesn't power ON right? its maybe your main board and not the T-CON board.You can check the fuse and the voltage on your T-con BOARD. And disconnect the t-con board and try to power up your TV. its should power on if the t-con board is cause a problem

Thank you for responding. The unit seems to go through a sequence when attempting to turn on, involving blinking LED/logo which switches to the normal white logo, yet the screen remains w/o a picture and is unresponsive to remote or Jog controls.

There appears to be power going to the T-Con and the fuse passes a continuity test. Disconnecting the T-Con has no effect on the power up sequence.

Since disconnecting the T-Con produces no change, is it likely a main board problem and, if so, is there a way to test the main board?

Thanks, again, for responding...I was ready to buy a T-Con (if I could find one) but now I'm rethinking that coarse.

[ecking767]

Re: Vizio XVT3D474SV No Picture, Blinking Logo

Thank you for responding. The unit seems to go through a sequence when attempting to turn on, involving blinking LED/logo which switches to the normal white logo, yet the screen remains w/o a picture and is unresponsive to remote or Jog controls.

There appears to be power going to the T-Con and the fuse passes a continuity test. Disconnecting the T-Con has no effect on the power up sequence.

Since disconnecting the T-Con produces no change, is it likely a main board problem and, if so, is there a way to test the main board?

Thanks, again, for responding...I was ready to buy a T-Con (if I could find one) but now I'm rethinking that coarse.

The flash of the LED/LOGO is normal, the LED it should STOP blinking on yellow, not white. The LED/LOGO should turn "White" when the power is button is press.If the last state is "White" then its your main board

You can check the fuses, regulator, and caps on the main board. Also check the HDMI chip and the main CPU for overheat. This is a smart TV so there is a good chance your EEPROM is corrupted you can try to resolder that chip as as a last resort. but be careful not to do solder bridges.

[Robb]

Re: Vizio XVT3D474SV No Picture, Blinking Logo

The flash of the LED/LOGO is normal, the LED it should STOP blinking on yellow, not white. The LED/LOGO should turn "White" when the power is button is press.If the last state is "White" then its your main board

You can check the fuses, regulator, and caps on the main board. Also check the HDMI chip and the main CPU for overheat. This is a smart TV so there is a good chance your EEPROM is corrupted you can try to resolder that chip as as a last resort. but be careful not to do solder bridges.

The fuses and regulator pass a diode test w/my DMM. The caps appear to be OK but I don't yet know how to use my ESR meter so I can't be sure yet. The HDMI chip shows no visual sign of overheating nor does the cpu (although it's hard to see under the heatsink).

I've read where this model commonly has EEPROM problems that require reprogramming (I been wondering if a Bus Pirate could reprogram). I'm not yet sure which chip is the EEPROM but I have a soldering/reflow station and lots of my homemade liquid flux for reflowing.

[ecking767]

Re: Vizio XVT3D474SV No Picture, Blinking Logo

THE EEPROM chip is under the heat sink shield. TSOP48 chip

[Robb]

Re: Vizio XVT3D474SV No Picture, Blinking Logo

THE EEPROM chip is under the heat sink shield. TSOP48 chip

Thank you. Looks like I need to desolder the heatshield to get to the EEPROM in order to reflow it.

The HDMI chip shorts to ground on pins 77 & 78. I'm trying to find a datasheet to see if that's normal.

[Robb]

Re: Vizio XVT3D474SV No Picture, Blinking Logo

While searching for info on EEPROMs & this model, I found a post where the IR module ribbon was damaged & caused the set to not power up correctly which led me to double check the ribbons & try to power up the unit. Unfortunately, it didn't fix my problem but it allowed me to notice the power up sequence was different from what I remembered.

More accurately - when plugging in the unit, the unit starts with a blinking yellow/white led/logo for about 1.5 minutes which then changes to a solid yellow. The unit remains in what appears to be Standby mode w/yellow led/logo until powered on by Jog button or remote which causes the led/logo to turn white. Once, the led/logo turns white the screen is usually black but the second to last time I powered it up the screen backlights lit up the screen with a transparent-like grey/white.

I'm going to meditate on this for a little bit before proceeding with attempting to reflow the EEPROM.

[Robb]

Re: Vizio XVT3D474SV No Picture, Blinking Logo

Still can't find a datasheet for the HDMI chip and the shorts on pins 77 & 78 are bugging me. Can't find a schematic for the main board either. Wish I had a good main board to see if the pin 77 & 78 shorts are by design or not.

Voltages on main board fuses are 5V, 11.8V & 18.8V for whatever that's worth.

[ecking767]

Re: Vizio XVT3D474SV No Picture, Blinking Logo

the state of your TV now is:TV power on, (with white logo) no back light, and wont power down with remote? Don't try power off with the Jog wheel because a quick menu will pop up asking you to select volume or channel, or power off etc...

You can also try disconnecting the LED driver board to see if the status changes

and if you know the last input the TV was using, hook up a source to try to get sound.

[Robb]

Re: Vizio XVT3D474SV No Picture, Blinking Logo

Yeah, when I plug the tv in the wall the VIZIO logo blinks amber (not really yellow) & white for over a minute & then it stays amber until I power it on.

When I power it on, the VIZIO logo turns white but there is no picture. At this time only, I am able to get 5V, 11V & 18V on the main board fuses. After a little while, the white logo starts blinking amber & white on it's own and then turns amber until I power it back on.

I will try unplugging the led board (I'm assuming it's the leftmost board) after Equador beats Honduras in the World Cup.

I have no idea what input was used last but I'll try plugging in as many devices as I can to see if they produce sound.

[Robb]

Re: Vizio XVT3D474SV No Picture, Blinking Logo

Unplugging the power cables to the led board produced no change on power up.

I watched the power sequence after hitting the power button a little longer and noticed it cycles endlessly between blinking amber/white > white > blinking amber/white > amber > repeat.

[Robb]

Re: Vizio XVT3D474SV No Picture, Blinking Logo

Correction: I watched the power sequence a little longer: after hitting the power button, it cycles endlessly between blinking amber/white > white > blinking amber/white > amber > repeat.

[MisterD]

Re: Vizio XVT3D474SV No Picture, Blinking Logo

I wouldn't mess with the EEPROM, sounds like a bad T-con board.

[Robb]

Re: Vizio XVT3D474SV No Picture, Blinking Logo

I wouldn't mess with the EEPROM, sounds like a bad T-con board.

Thank you for your input. I was considering getting a new main board...perhaps, I should be considering a new t-con. I have read that the t-con can be difficult to diagnose.

[Boroth]

Re: Vizio XVT3D474SV No Picture, Blinking Logo

Robb.....I am having a similiar issue with this same exact TV. I have the TCON board out and have reflowed all the chips that are covered with heatsinks. Afterwords I decided to go through and check out the caps on the board as several look to be slightly bulged. To my amazement it was two lesser caps that are producing some strange results.

Cap at CE28 is Labeled OE 470 EZD and when using the continuity feature of the meter (just a first test sort of way I like to check capacitors in circuit to test for blown out caps) this one is reading far far far lower then the other similarly mark caps on the board. The Buzzer is going off and it is reading 016 when all of the other fuses marked the same are reading in the 1380 range and no beep.

Cap next to it at CE8 is marked OP 220 CLA. Same thing....reading 014 and buzzer going off. Other caps marked the same on the board are all reading around 530.


Can you check what those are running for you if you still have access to this board please. May help me in the repair of this board!

[joto1000]

Re: Vizio XVT3D474SV No Picture, Blinking Logo

Is there a Vizio error code manual out there that may be cross referenced with the number of times the Vizio logo flashes? I have a three year old M470NV where the picture froze, but sound kept streaming. Then after a few minutes the screen went black and the Vizio logo began flashing from orange to white 24 times and continues that cycle. I've unplugged the tv for hours and days and it still has not resolved itself. I'm assuming that the number of times the logo flashes may be an indicator of what the problem is? Thanks.