HDMI Experts - what can cause this type of behavior? - AVS Forum
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post #1 of 13 Old 12-14-2011, 07:42 PM - Thread Starter
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I apologize if there was a better forum for this. This is a multi-component issue, but since some of the components involved are LCD/LED displays, this isn't entirely out of place.

Long story short (as possible):

New custom HTPC and new Vizio XVT323SV Television (LED 1080p). When the television turns on after being off for at least 20-30 minutes I get strange flickering and artifacts. This flickering is a distortion of the image akin to a loose analog cable connection. It can start off very strong, distorting the entire screen or it can begin just as a few flickering random lines. When the entire screen is distorted it can almost looks like shattered glass with lines of green and purple. The issue will persist from anywhere from 20-120 seconds, lessening in intensity and duration until it completely disappears.

The screen then remains normal for the duration of the viewing session and only will reoccur the next time the TV has been powered off for an appropriate amount of time.

The distortion I explain above is when the PC is booted into Windows. If I boot into the BIOS only (which is UEFI and therefore graphical) I get disturbance in the form of fuzziness and flickering which also goes away after a similar duration.

I was able to get my hands on another 720p TV and a Roku player. I connected the Roku player to my Vizio and my HTPC to the 720p TV. I figured that whichever one continued to manifest the issue was the faulty component.

Unfortunately, neither display seems to exhibit problems in this setup. So, if it isn't the TV...and it isn't the PC - but only them together - how do I figure out which one is the cause?

I don't think this is a "PC" issue (driver/refresh rate/etc). Or a cable issue. The main reason for not thinking this is that the problem only happens when the TV has been off for the appropriate amount of time and then only persists for a short duration. I would think that if it were one of the above issues the problem would persist throughout and not just fade away.

I don't really know what else could be causing the problem, or how to further try an isolate the issue. I am going to be try bringing the PC over to my in-laws tomorrow to try it on their HDTV as one other test - but assuming I don't get any interference, I'm at a loss of what else to try.

Please advise!
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post #2 of 13 Old 12-14-2011, 08:37 PM
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20-130 seconds could indicate some component or connection is failing and get's fixed after short warm up.
BIOS probably uses lower resolution and therefore may show less pronounced problem, but it's there so I would lean towards video card in your computer: it hits up fast, uses less resources and low resolution in BIOS, so may show different problem than normal full resolution bootup etc. It could be as simple as reseating the card in PCIe slot or could be memory, GPU or capacitor failure, who knows?
TV could be a problem if passing test was done with different resolution than when used with computer. I'm assuming you already checked all the obvious, like cables etc.
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post #3 of 13 Old 12-14-2011, 09:17 PM - Thread Starter
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Hi Pete,

Thanks for your advice.
Actually this is an AMD A8-3850 processor with an integrated Radeon graphics processor. So there is no discrete graphics card or, indeed, even one integrated into the Motherboard. Of course the Motherboard does supply the necessary connections to route the video to the CPU.

I am leaning towards the motherboard being an issue - but really have nothing definitive. The maximum resolution on the PC video is 1920x1080 @ 60Hz which is what it is set to under Windows. Under the BIOS, I cannot say what the resolution is.

The Vizio TV that it is experiencing issues with is a 1080p 120Hz TV.
I have also tested it against my 720p Sanyo Z3 Projector (unknown refresh rate) and an Element 19" 720p 60hz TV. I seem to only be experiencing these problems with the Vizio.

I can't see this being a resolution/refresh issue for two reasons. 1) The issue only lasts for a short period of time and 2) This isn't the scrolling type of flicker that refresh rates tend to cause. This is a more of a random jagged line flicker. I have posted a video I just took here (comments on video). Unfortunately I was able to only catch a minor occurrence of the problem not one of the lengthier fits where the whole screen goes kind of bonkers.

I also think that a bad cable wouldn't exhibit only this temporary behavior. As I mention it only lasts for 20-120 seconds and also only if the TV has been off a while. I did purchase relatively cheap cables (online deal and some from Frys) but they are rated high-speed and they seem to work fine with everything else.

It's frustrating since I can't recreate this issue with a different combination on either end. I have more tests with the computer going into multiple inputs (and will have one more tomorrow) but have a limited number of HDMI input sources to test.
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post #4 of 13 Old 12-15-2011, 08:38 AM
 
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Quote:
Originally Posted by Bengalih View Post

Hi Pete,

Thanks for your advice.
Actually this is an AMD A8-3850 processor with an integrated Radeon graphics processor. So there is no discrete graphics card or, indeed, even one integrated into the Motherboard. Of course the Motherboard does supply the necessary connections to route the video to the CPU.

I am leaning towards the motherboard being an issue - but really have nothing definitive. The maximum resolution on the PC video is 1920x1080 @ 60Hz which is what it is set to under Windows. Under the BIOS, I cannot say what the resolution is.

The Vizio TV that it is experiencing issues with is a 1080p 120Hz TV.
I have also tested it against my 720p Sanyo Z3 Projector (unknown refresh rate) and an Element 19" 720p 60hz TV. I seem to only be experiencing these problems with the Vizio.

I can't see this being a resolution/refresh issue for two reasons. 1) The issue only lasts for a short period of time and 2) This isn't the scrolling type of flicker that refresh rates tend to cause. This is a more of a random jagged line flicker. I have posted a video I just took here (comments on video). Unfortunately I was able to only catch a minor occurrence of the problem not one of the lengthier fits where the whole screen goes kind of bonkers.

I also think that a bad cable wouldn't exhibit only this temporary behavior. As I mention it only lasts for 20-120 seconds and also only if the TV has been off a while. I did purchase relatively cheap cables (online deal and some from Frys) but they are rated high-speed and they seem to work fine with everything else.

It's frustrating since I can't recreate this issue with a different combination on either end. I have more tests with the computer going into multiple inputs (and will have one more tomorrow) but have a limited number of HDMI input sources to test.

Let's go through a few things. Your idea for the test was great except you have to make sure your setup is exactly the same. When you talk about a 720p TV for the test, was the input resolution to the 720p TV exactly the same as the 1080p Vizio? In other words was 1080p (or whatever resolution you are sending out from the HTPC) the same with the 720p TV as well as the Vizio LCD? If not, this will change the speed of the HDMI transmission and invalidate the test results.

Instead, with the HTPC hooked up to the Vizio LCD, change your HTPC resolution to 720p and see if the problem reoccurs. If it does, then maybe it is a cable issue. If it doesn't then I'm thinking there might be a firmware issue with the Vizio. Check the Vizio website for firmware updates.

Unfortunately trying to pinpoint an interface/handshaking issue is timeconsuming. Often the manufacturers will point fingers at the other side of the interface and claim it's not their problem. That makes it even more difficult to figure out where the problem really is.
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post #5 of 13 Old 12-15-2011, 12:26 PM - Thread Starter
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Thanks Alk,

Yes I did try bringing the resolution both up to 1080 on the 720p TV and also down to 720 on the 1080p TV. The issue continued to occur only on the Vizio.

The Vizio is running the latest firmware.

The good news is I came out late last night after the TV had been off 2-3 hours (most of my tests I only wait 30 minutes). When I turned the TV on switched to the Roku I got fuzzy disturbance lines similar to those I get under the PC BIOS.

This goes to show that I am getting weird output from two different input sources - so it is most likely the output source - the TV!.

I may go and spend some money on a really expensive Monster cable - to see if that's the problem...but I really think my cables are fine. The are low cost, but high-speed - and I've tried 3 of them from 2 different manufacturers.

Might get a better video up in a bit that shows the issue more.
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post #6 of 13 Old 12-15-2011, 01:55 PM
 
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Please don't get the Monster cable. It's the same. If you are unsure of your cable source, get a Monoprice high speed cable. They are a known good source and you won't overpay. For the price of the Monster you can get the best high speed Monoprice cable and overnight shipping.

Can you post a picture of the sceeen when you have the problem? Edit - sorry didn't see the video link in your initial append.

I'm actually wondering if this is a cable or TV HDMI input problem. Try swapping HDMI inputs and see if the problem follows.
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post #7 of 13 Old 12-15-2011, 04:44 PM - Thread Starter
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Alk,

Thanks again. I was saying Monster because I can pick it up locally and return it when it turns out not to be a cable issue. Wouldn't a Cable issue cause the problem to occur more frequently, and also exhibit itself with other sources?

Granted, the other output sources were 720 not 1080, but even with resolution set to 1080 on the input sources, the issue only appears on the Vizio.

I have tried all 3 (or 4) HDMI inputs on the TV - and this happens over all of them.

Here is another Video with annotations that much more clearly shows what I am experiencing.

Thanks
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post #8 of 13 Old 12-15-2011, 05:26 PM
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My bet is a TV issue... your video stage in your tv has an "stability issue" with either power supply and /or signal processing... for example there may be some issues with "overlays" as in menu versus input etc. This could also be related to the "120 magic" that supposed to "help". Depending on your skill and setup, you could try "hair drying" (ie. blowing heat) on the back at selected areas of the "boards" (ie. input stage, video processing, etc). Try this after the set has been off for your suggested "problem generation time" (ie. 20 min). Then see if "heating" cures the issue or causes thing to change. OF course, be careful when playing with both heat "things" and electronics... AND plastics. Good hunting.... if the TV is under warranty, then I would just head in that direction.
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post #9 of 13 Old 12-15-2011, 05:36 PM - Thread Starter
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Yes, I tend to agree it is a TV issue.

Luckily, the TV is still under return period at Sams Club. Unfortunately, they are out of stock and will likely not get anymore in. This is the only 120Hz/1080/LED 32" TV out right now (that I can find) and was a decent price to boot.

I'm probably gonna hold onto it for another couple weeks to see what I can find. Another price drop might come and I can get it from elsewhere. There are some other things about the TV I'm not crazy about, so maybe I bit the bullet and just look at 60Hz sets instead.

I'll still try another cable once I get a hold of one - but I don't think it will help :/
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post #10 of 13 Old 12-15-2011, 05:48 PM
 
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Quote:
Originally Posted by budwich View Post

My bet is a TV issue... your video stage in your tv has an "stability issue" with either power supply and /or signal processing... for example there may be some issues with "overlays" as in menu versus input etc. This could also be related to the "120 magic" that supposed to "help". Depending on your skill and setup, you could try "hair drying" (ie. blowing heat) on the back at selected areas of the "boards" (ie. input stage, video processing, etc). Try this after the set has been off for your suggested "problem generation time" (ie. 20 min). Then see if "heating" cures the issue or causes thing to change. OF course, be careful when playing with both heat "things" and electronics... AND plastics. Good hunting.... if the TV is under warranty, then I would just head in that direction.

I have to agree with budwich after seeing the video. The flickering is definitely not HDMI. That has an analog "look" to it whereas I'd expect an HDMI problem to result in a blank screen and not have a consistent place on the screen where the problem resolves.

Given you have a Sam's Club warranty, I'd take it back as quick as possible and first try another of the same model since it probably is a manufacturing defect. If this is heat related, the problem could get worse over time.

Here's another option.
http://www.amazon.com/Sharp-AQUOS-LC.../dp/B002BNMPC0

I think Sony also has a 32" LCD with LED backlighting.
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post #11 of 13 Old 12-15-2011, 06:19 PM - Thread Starter
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Thanks guys.

I should have been more specific re: available TVs. I got this TV (XVT323SV) for $430 (+~$45) tax from Sam's. I actually could have ordered it from Amazon the week before for $430 (sans tax and shipping), but decided to pick it up locally.

This TV really has a lot of features 1080p,LED,120Hz, Web Apps. And at under $500 it really beats the pants off everything in its price range.

There are a couple other 120Hz sets out there, but they go for like $200 more. Many of them seem to be discontinued models (which may account for their increase in price, because they are hard to find).

I think $600-700 for a 32" is excessive...especially if it is not 3D and doesn't have Web apps built in.

In all honesty, I don't need the Web Apps, as I will use the HTPC (but they would be nice to have if the TV gets re purposed to another room). I also don't think I really need the 120Hz. I would prefer to keep the 1080 even on the 32", but I really don't watch a lot of live sports or too much gaming, so a lower refresh may still be ok.

I'll still probably end up spending $350-400 for a good 1080p/60Hz...and even at that might have a hard time finding an LED one.

So yeah, it was a great value for the money, and if I can find it again over the next couple weeks I might try a second set to see if it was just the one I got. Otherwise, I'll just keep my eye out for a good deal.
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post #12 of 13 Old 02-25-2012, 01:35 PM - Thread Starter
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Just wanted to update this thread to let anyone who might be experiencing similar issues know that this was indeed a TV issue 100%.

I replaced the TV with an identical model and the issue was completely gone.

Sorry for resurrecting the thread, but I always hate finding old threads that completely explain my issue but don't offer a final resolution!
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post #13 of 13 Old 02-25-2012, 02:58 PM
 
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Quote:
Originally Posted by Bengalih View Post

Just wanted to update this thread to let anyone who might be experiencing similar issues know that this was indeed a TV issue 100%.

I replaced the TV with an identical model and the issue was completely gone.

Sorry for resurrecting the thread, but I always hate finding old threads that completely explain my issue but don't offer a final resolution!

We appreciate knowing how things worked out. Thanks for taking the time and glad you got the problem resolved!
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