Vizio P-Series 4K tv with temporary sound and no picture P652ui-B2

[SLK001]

Re: Vizio P-Series 4K tv with temporary sound and no picture P652ui-B2

Q: Is there a possibility that all of this trouble on the right-hand side of the screen could be caused by a faulty ribbon running from the Digital Main Board down to the T-con board.

It is possible, but it is not probable. You could test the continuity of the cable, if you are careful.

Be sure to inspect the top of the panel for bad caps, or even assembly damage. There should be a PCB strip or two where the cables from the TCON connect to the panel.

[kca]

Re: Vizio P-Series 4K tv with temporary sound and no picture P652ui-B2

Yes, I think these Digital Main Board to T-con cables might be problematic, but not in the same way as the T-con to panel cables because the former have metal connectors where the ribbons are already “implanted” inside the metal ends.

Could they be torn or loose on the inside of the metal. I suppose. Not likely, perhaps, but it would go a long way toward explaining the white/pink/green screen on the left-hand side.

Do you think, then, that a faulty Digital Main to T-con cable can indeed produce these results?

[kca]

Re: Vizio P-Series 4K tv with temporary sound and no picture P652ui-B2

Thanks, also, SLK001. Can you please take a look at the full photo of the back panel design and board configurations and let me know if this “jives” with your last post and suggestion?

What I’m wondering, specifically, is if I should be inspecting the top of the panel or the bottom more so based on the positioning of the T-con board (bottom center, underneath the black plastic cover in that particular photo), or should I focus on the top of the panel because the LED Inverter Board is located up in the upper center of this set’s configuration?

[SLK001]

Re: Vizio P-Series 4K tv with temporary sound and no picture P652ui-B2

The panel boards should be under here:

https://www.badcaps.net/forum/attach...1&d=1541212785

[kca]

Re: Vizio P-Series 4K tv with temporary sound and no picture P652ui-B2

Thanks for that image and the clarification, SLK. Yes, I think I’ll have to remove the whole bezel to get at them.

As far as the continuity test on the ribbons going from Digital Main to T-con, I just tried it but not sure if I did it right.

First, disconnected the two ribbons from the top of the T-con board (with the power off, of course), then applied power.

Then, set the DMM in continuity mode.

Grounded the black wire against the chassis and dragged the red probe across all of the exposed pins at the end of the now disconnected metal connectors. Did both the thin ribbon, which controls the right-hand side of the picture, as well as the thicker cable (left-side of picture).

On BOTH cables, I got about 9 or 10 cable-end tips (gold colored) to signal with the continuity “beep”. Most pins didn’t. There are about 30-35 pins on each connector. So, maybe 1 out of every 3 or 4, overall, but there was no detectable pattern.

Did I do that correctly?

(Seems like the thicker cable should have tested noticeably different than the thin one, but it really didn’t).

[kca]

Re: Vizio P-Series 4K tv with temporary sound and no picture P652ui-B2

By the way, just to illustrate that all of the backlights are all coming on, I was able to take this image of the back panel the last time the tv randomly lit up about an hour ago:

[budwich]

Re: Vizio P-Series 4K tv with temporary sound and no picture P652ui-B2

Thanks for that image and the clarification, SLK. Yes, I think I'll have to remove the whole bezel to get at them.

As far as the continuity test on the ribbons going from Digital Main to T-con, I just tried it but not sure if I did it right.

First, disconnected the two ribbons from the top of the T-con board (with the power off, of course), then applied power.

Then, set the DMM in continuity mode.

Grounded the black wire against the chassis and dragged the red probe across all of the exposed pins at the end of the now disconnected metal connectors. Did both the thin ribbon, which controls the right-hand side of the picture, as well as the thicker cable (left-side of picture).

On BOTH cables, I got about 9 or 10 cable-end tips (gold colored) to signal with the continuity “beep”. Most pins didn't. There are about 30-35 pins on each connector. So, maybe 1 out of every 3 or 4, overall, but there was no detectable pattern.

Did I do that correctly?

(Seems like the thicker cable should have tested noticeably different than the thin one, but it really didn't).

don't understand what you are trying to test???? whether there is a ground at the connector or whether there is end to end continuity in the cable?

[kca]

Re: Vizio P-Series 4K tv with temporary sound and no picture P652ui-B2

I am assuming that SLK was asking me to try to test the end to end cable continuity.

I was thinking that the thicker cable would show little or no flaw, and that the thin one might reveal something noticeably wrong. But, with both beeping on multiple and various end pins, it didn’t give me any immediate answers. Is there another way I should be approaching this?

I want to test the viability of the cables. And anything else that would get me closer to solving the picture problems found on this set.

[budwich]

Re: Vizio P-Series 4K tv with temporary sound and no picture P652ui-B2

end to end continuity on a cable is tested by testing each individual pin to the equivalent pin on the other end. All you did was check to see if any pins are "grounded" (connected) to the connector case. No sure that shows much unless you know which pins are supposed to be and which are not. I would expect some to be as that is "normal" for signal transfer (grounding). Once the continuity test is done further "adjacent" testing can be done on ribbon cables (and other types of cabling) to rule out "burn thru" or "inter-pin" connections if desired.

Further: re-reading what you did / said. You powered up the set and then tested the one of end of the disconnected cable by running the probe across the pins of the connector. yikes!

First, continuity using a DDM in continuity mode is done without powering the circuit under test. Continuity is a resistance measurement made by the meter using its own power. Any other power "entering" the circuit will cause issues. I am not sure what a meter in continuity will give when the circuit is under power and the "reference point" (ie. black probe) is "case ground" assuming that the circuit is design as such. Likely OK since any pins "linked" will likely have no potential (voltage).

You might want to rethink what / how you do things.

[SLK001]

Re: Vizio P-Series 4K tv with temporary sound and no picture P652ui-B2

I am assuming that SLK was asking me to try to test the end to end cable continuity.

Yes, end to end continuity.

[kca]

Re: Vizio P-Series 4K tv with temporary sound and no picture P652ui-B2

Gotcha. That makes sense. I’ll do the end to end test with the cables completely disconnected from the two involved boards.

[kca]

Re: Vizio P-Series 4K tv with temporary sound and no picture P652ui-B2

Well, I didn’t find anything abviousky wrong with the two ribbon cables leading from Digital Main to T-con (though it was indeed hard to test each individual pin set for end to end continuity).

I’m contemplating taking the bezel off next, but before I do that I would like to be assured that this effort will potentially detect a problem. In other words, is this Vizio LCD panel designed so that an error underneath the bezel can ACTUALLY result in the half-picture on the right-hand side (only) to be absent?

The T-con is obviously designed in this dual manner to split the signal, but does the panel necessarily and absolutely have this same type of design? Namely, if I take off the bezel, will I be finding two separate panel boards?

Can anyone direct me to a picture or a schematic that will answer the above questions?

Thank you in advance.

~ kca

[SLK001]

Re: Vizio P-Series 4K tv with temporary sound and no picture P652ui-B2

I can't speak with any authority about your TV. Here is a picture of a 50" panel that has problems. There are mostly caps and resistors on these strips - it's possible that a cap could be broken, shorted or otherwise damaged, which can cause problems with display on one side.

This strip is located under the bezel and there are two of them. They usually run about half the width of the panel. You can see where the TCON connects to the strip.

https://www.badcaps.net/forum/attach...1&d=1541381851

[kca]

Re: Vizio P-Series 4K tv with temporary sound and no picture P652ui-B2

Thanks, SLK ~

Am I correct in assuming then, at this point, that it is either this “panel board” (sometimes called the E or F buffer, I believe), OR it might be a fault in the Digital Main Board itself?

{I’m asking with the mindset that it is not either the T-con or the cable ribbons leading from Digital Main to T-con.}

If my first query is true, based on all the symptoms involved what % would you say the likelihood is that it’s this lower panel board vs. the likelihood that it’s the Digital Main?

I’m asking that because I just did an extensive online search for this lower panel board (in case I cannot repair it if it’s damafed) and I couldn’t find a single image let alone a replacement part. On the other hand, Digital Mains for this particular Vizio tv are readily available. More expensive than I’d like, but available and I could purchase one if there’s a good enough chance that this flaw is actually originating within the Digital Main itself. Is that a possibility and/or a probability given the nature of the white/pink/green half-sceeen?

[budwich]

Re: Vizio P-Series 4K tv with temporary sound and no picture P652ui-B2

its pretty tough for the main board to cause an issue on a panel when the cables on that side have been disconnected.... it would be "magical"... electrons flowing thru the air... :-)

it is more likely that your problem is from the tcon "down". Because of the lack of "consistency / predictability / repeatability" in your results, it is hard to determine much. Not sure what that means other than keep trying things until something "stabilizes".

based on some of the things you have "produced", my guess is that there is "issues" with the edges boards at a minimum. The edge board components (smd caps and resistors) can be replaced with some soldering skill. It is unlikely that a repair shop effort would be economical as labor both in terms of dismantle / mantle and troubleshooting would be significant.

Having said this, I am not sure that I understand the reluctance of taking off the front bezel to examine the side tabs as ultimately these sets are known to have failures there and those may result in a variety of "conditions / display issues".

[kca]

Re: Vizio P-Series 4K tv with temporary sound and no picture P652ui-B2

Thanks for the detailed reply, budwich. I will go ahead and take the bezel off and report what I find. Just was a bit reluctant because I have found that the more I tear down a set the more likely it is that it ends up sitting for months with no resolution.

I mentioned the Digital Main Board as a potential source of the problem because whenever I disconnect either of the two cables that run either out of it (and toward the T-con) then all power is denied to the screen. There is no cycling or any attempt by the set to initiate a picture at all. So, if there was a signal fault on the Digital Main, it would be “masked” by the denial of continuity running from the Digital Main Board “downward”.

Not sure if that helps to explain my reasoning. I can do more testing if that would help clarify.

It’s probably in the panel edge board and its components, as you said. I did take a hair dryer two days ago and tried to hold it over these bottom edge panel boards (where the 4 white ribbons go from T-con into those final 4 connectors at the very bottom edge), without damaging the cables themselves with the heat ...... but there was no change in the “mostly off / occasionally on” pattern or as it relates to the overall activation of the screen.
Was hoping that if it was a dying but not dead cap or component, the heat would act as a trigger. Never really used the freeze spray yet. Would that be a better way to test once I get the bezel off?

[kca]

Re: Vizio P-Series 4K tv with temporary sound and no picture P652ui-B2

Hello all ~

I did take the bezel off this 65” Vizio today and inspected every SMD I found. I did this just on the two left-hand bottom panel boards as that’s the side likely causing the right-hand side of the tv’s screen to display incorrectly.

Took a while to test them all, but I found 1 SMD capacitor (and only one, really) that I think is causing the issue. While all the others (and there were dozens and dozens of others) all showed quite patterned results when I had the DMM in Diode / Continuity mode, this one particular SMD capacitor was erratic at best.

This cap is labeled C114. It also has the capital letters RSEQ (or, maybe RSEO?) printed below it on the board.

My first 10 readings of it or so showed no decipherable readout. It would flash a value of over 1,000 momentarily on the DMM, then go to a readout of 1.

Then, for just a moment, I got a reading of 616, indicating that maybe it wasn’t completely dead. Then another dozen or so times with no good reading (just like the first 10 times noted above). Probably tested it over 50 times and it only read good (meaning, 616) twice in that time span.

Then, kind of inexplicably, I got the 616 readings about 5 times in a row before it reverted back to the problematic readings, which it did another several dozen times.

I took several close-up pictures (see below) and thought I had noticed that the solder joint might be bad on the upper side of the capacitor. And so, since I had come this far, I decided to drop a tiny amount of solder to see if I could complete the connection.

Long story short, it didn’t work. Tried it a few times. No dice.

So, I’m hoping a few of you out there can take a look at the pictures below and provide your thoughts and answers to the following:

1) Is this SMD capacitor very likely defective, especially due to what looks like two tiny pinholes on its top? Is that an indicative sign that a cap like this is on its last legs and/or already defective?

2) If it needs to be replaced, I think I can do that after I get a heat gun. I’ve watched enough online videos of the process over time to know it’s not a real complex process. But, how do I know exactly which capacitor to purchase when there is no value printed upon it?

Is it possible that the value is stamped on the underside, and can only be seen after it is taken off the board?

I found the User Manual and Quick Start Guide online for this Vizio P652ui-B2 model (see link below) but I’m having trouble tracking down the Service Manual itself which would likely tell me the cap’s value.

https://www.manualslib.com/products/...2-3611398.html

3) Is this type of cap (and, faulty cap at that) capable of causing the white / pink / green half-screen that is so continually problematic on this set? Can one, singular small cap of this type cause so much trouble?


Note: The last image of the 3 below is the one that led me to think that there was a broken solder juncture. If you look closely at the upper-right corner of this SMD capacitor, you’ll probably see what I saw ..... where it looked like the connection had been broken.

[SLK001]

Re: Vizio P-Series 4K tv with temporary sound and no picture P652ui-B2

Service manual? Don't kid yourself - you have a better shot getting picked for the next moon landing than finding any more service manuals.

Your pics are not high enough resolution to be able to see what you are seeing. The cap looks like a 0805 version, which means that it is probably in the 1.0 -4.7uF range. If a cap with that high a value is bad, all kinds of noise could appear on the output, which could cause issues. If you can't determine the value, just replace with a value near 2.2uF. The two sides should be almost identical, so you might be able to find this guy's mirror on the other side.

As for removal with a heat gun (unless it is a soldering station), I wouldn't. I use two soldering irons for SMD chip removal and replacement. I hold them like a pair of tweezers and effect the repair.

[kca]

Re: Vizio P-Series 4K tv with temporary sound and no picture P652ui-B2

Great insight and advice. Thank you on both counts.

Vizio seems particularly bereft regarding online service manuals, so I’ll just probably go with the 2.2uF suggestion you made. Agree that it does look like an 0805.

Is the heat gun not targeted enough? Too imprecise, I suppose, for such a small SMD and another, even smaller one, about a millimeter or less away.

I will use the mirror idea to compare all the left-side vs. right-side values. I was concerned about a vertical patch on the “good” half of the screen that was sometimes black, sometimes green, and sometimes okay. Probably just the T-con to panel ribbons being a little bit off there, but the value comparisons will help me figure that out as well.

Here’s one other piece of information that may or may not help. As I’ve mentioned, I can’t get any reading on this particular damaged SMD cap more than 95% of the time (and the last 20+ times in a row), so I think it’s now dead. However, when I put the DMM in Ohms mode at the 2000 range, this same cap would consistently read 850. Is that to be expected? And, does that provide any clue as to the exact, multifaceted set of values that I should be searching for when I buy its replacement?

In particular, I’m concerned about getting the proper voltage (seems like 10v, 16v, and 25v are the most available versions), and what is the difference, if any, between X5R and X7R versions?

[budwich]

Re: Vizio P-Series 4K tv with temporary sound and no picture P652ui-B2

your best bet is to "compare components side to side" as best you can.

Range selection in the resistance measurement changes what potential is used to drive the "circuit" under test. Of course, in a low range, you don't want a circuit to be driven by a large "battery" as that might be dangerous while in a high range, a "low battery" source might not provide enough current to cause a reading... hence the differences.

However, for capacitance "resistance testing", the charging rate will vary based on the capacitor and the voltage used to charge, hence when you test a capacitor,its reading of "impedances" changes as it charges. Your testing of that capacitor may indeed show that it has a high resistance or not... first, you don't know exactly what value it is, and it is "in-circuit" so other components may be interfering with the test result. This is true for the others as they may be in parallel with other components changing the readings. The "mirror comparison tests" may help but ultimately the suspected component may be need to be removed to properly test it.

As for removal, I wouldn't use a heat gun as it may find its way toward the panel... :-(
Use some flux and heat one side of the smd and then the other... kind of back a forth until you see the solder "shine"/melt then your solder iron will likely be able to slide the component a bit off the pads and no longer be "attached" to the board (and may even stick to the iron tip).