Vizio E470VL - Lines & garbled image....sometimes

[Topcat]

I've got a stumper, I can't pinpoint whether it's a tcon, tab bond, or signal process issue. Temps cold/hot don't seem to affect it....sometimes it's just perfect as can be, most the time it looks like this:





This is an overscan crosshatch, where it appears ok....but it's still doing it.



I've cleaned the ribbon contacts till I'm blue in the face, no change. Poking/twisting/applying pressure to the signal processor/TCON board doesn't change anything...neither does it change anything with the tab bond PCB's. There's no rhyme or reason to the malfunction at all....as a matter of fact, as I typed this, it straightened itself right out and is pretty as a picture (pun intended).

PSU is putting out correct & stable voltages....I'm kinda baffled by this one....perhaps some of you more experienced TV guys might have some feedback. This belong to a customer, dropped off with the usual instructions of "I don't want to spend a whole lot" ...and I'm not a tech to feed parts until the issue goes away...but not being able to narrow this one down isn't helping. This is the first one I've not been able to isolate to either the panel (bad tab bonds) or the signal processor/TCON board (integrated onto one board with this model). If it's the panel, obviously the set is a goner.....I searched the panel number (LG LC470WUH), and no red flags came up of them being problematic....but I'd certainly like something more positive before I pronounce it.

The boards:





Any input would be super.

[Diah]

the panel LC470WUH 120Hz 3D one. for testing need to use 1080P photo mage only (not pattern image)
if the displaying show perfect picture after while , its of sure currents issue at PSU. Volts are corrects but with no juice (currents)

[Topcat]

Originally Posted by Diah

the panel LC470WUH 120Hz 3D one. for testing need to use 1080P photo mage only (not pattern image)
if the displaying show perfect picture after while , its of sure currents issue at PSU. Volts are corrects but with no juice (currents)

"Photo mage" Something lost in translation? What is that?

Maybe you're onto something, some patterns would display fine, while others would garble when running the burn-in loop. Voltages were correct with the set powered on, but not fed any signal....but when displaying some patterns (all are in 1080P), I could hear a faint whistle/buzz/hiss from the area where the ribbons interface with the tab bond panels.

That said, some of the 'troublesome' patterns would also display perfectly at times. The PSU is made by Delta.

[Diah]

Originally Posted by Topcat

"Photo mage" Something lost in translation? What is that?

Maybe you're onto something, some patterns would display fine, while others would garble when running the burn-in loop. Voltages were correct with the set powered on, but not fed any signal....but when displaying some patterns, I could hear a faint whistle/buzz/hiss from the PSU area.

That said, some of the 'troublesome' patterns would also display perfectly at times. The PSU is made by Delta.

photo image. at TV platform could be simple jpg or video img/mp4
resolution supported by the panel the highest 1080P, so we need to use only highest resolution which are the best will be ( Photos )to displaying.

[Topcat]

Originally Posted by Diah

photo image. at TV platform could be simple jpg or video img/mp4
resolution supported by the panel the highest 1080P, so we need to use only highest resolution which are the best will be ( Photos )to displaying.

I edited my above post before you responded....but the patterns are in 1080. Sencore VP403 supports these resolutions. I did connect a PC. I'll recheck the PSU out voltages. The whistle/buzz/hiss is coming from the top of the panel somewhere, not the PSU...as per the edit. It changes with various images.....kind of a benign symptom, I hear this in lots of sets.

[Topcat]

As before, being driven in max resolution.....







Desktop



I measured the voltages with each varying image, there was no fluctuation.



1) 5.3v
2) 5.3v
3) 5.3v
4) GND
5) GND
6) GND
7) GND
8) 12.3v
9) 12.3v
10) 12.3v
11) 2.4v
12) 3.4v
13) 0.2v
14) 2.4v

Just a FWIW.....note how garbled the window is, but the text behind it is perfectly legible.....just a bizarre observation.

[budm]

Pictures of the T-CON board?

[Topcat]

Originally Posted by budm

Pictures of the T-CON board?

Here's the high resolutions of the ones above.





The tcon and signal processor are all one board on this model. If you need closer up I can get you some tomorrow.

[Diah]

in such issue of distributed displaying we need to Testing the set with out any out source video processing circuit, such you are now using HDMI Input. USB INPUT or TEST CH48 Tuner signal ...are direct methods for test, as both using the SET video processing circuit.

so in case you dont have RF Channel test equipment's ..Copy different resolution test JPEG Photos on USB drive and play them direct on the set.

[Topcat]

Originally Posted by Diah

in such issue of distributed displaying we need to Testing the set with out any out source video processing circuit, such you are now using HDMI Input. USB INPUT or TEST CH48 Tuner signal ...are direct methods for test, as both using the SET video processing circuit.

so in case you dont have RF Channel test equipment's ..Copy different resolution test JPEG Photos on USB drive and play them direct on the set.

I already did that. Same garble on all inputs (RF & composite). Startup splash is also garbled, as is the OSD functions. Issue is after signal processor. TCON or panel/tab bonds as I initially thought....just need to pinpoint which.

[Diah]

Originally Posted by Topcat

I already did that. Same garble on all inputs (RF & composite). Startup splash is also garbled, as is the OSD functions. Issue is after signal processor. TCON or panel/tab bonds as I initially thought....just need to pinpoint which.

LVDS could be issue too.. so they need deep inspection at both ends with very good magnifier

[Diah]

one things more could be issue too. the MFC section at firmware.. from service menu if you do hard reset will be enough.

so for me i dont think its hardware (parts) defect. just the points i mentioned or we have leak bad soldering some where..

[Topcat]

I've tried every trick I know of to access the service menu....not working. https://factory-reset.com/wiki/Vizio_Service_Menu

FWIW, when it was cold, it displayed perfect for about ~5 minutes....then garble.

[Diah]

Originally Posted by Topcat

I've tried every trick I know of to access the service menu....not working. https://factory-reset.com/wiki/Vizio_Service_Menu

FWIW, when it was cold, it displayed perfect for about ~5 minutes....then garble.

so you are close to narrow the issue, use freeze air spray . starting from secondary circuit at PSU and the T-CON section at main board/nand / eeprom etc.

[Topcat]

Originally Posted by Diah

so you are close to narrow the issue, use freeze air spray . starting from secondary circuit at PSU and the T-CON section at main board/nand / eeprom etc.

What's the secret for the service menu though...that one is bugging me. I've never had one I couldn't get into.

[Diah]

search after main boards No. not model. Vizio some models belong to other brands..

about cold or warm state it garble. when it start garble plug it from wall socket and plug it on again. if it show clear display then its MFC FW. if it garble then its related to cold & warm of parts

[Diah]

i found on net .. service menu from the panel at the tv side press menu and immediately followed with power

[Topcat]

Maybe its getting narrowed here. Cold air anywhere on the PSU renders no changes. Same with the tab bonds, nothing changes. If I blast the tcon/signal processor board, things happen. The 'garble' changes patterns but never straightens out. Looks like perhaps some reflowing is in order.....but atleast it eliminated the PSU and the tab bonds.

[Topcat]

The focus of attention is now this chip/area.



If I hit that chip with the air, the display goes nuts and actually freezes up until the chip warms back up. Never do I get a 'normal' image on the display.

Hitting the CPU (inside the can) has no affect. Neither do any of the tuners/IO areas. It's down to something in that TCON chip area (tcon was my original suspect, but couldn't confirm).

I've reflowed this area several times, it has no corrected the issue.

[budm]

There are some SMD Lytics cap in that T-CON section on the main board, may be you can try pin point cold spray on those caps.