# HDMI cable is causing my picture to flicker?



## Doc99

I purchased an inexpensive HDMI cable from Monoprice, and since I connected it, there has been a flickering on the screen. the image will jutter for a second then stop. It will come and go. I switched back the component cables, and the image is normal. I am now wondering since it is the HDMI cable, should I return it and buy a better quality cable, or is this a common problem that is inherent in HDMI cables? I like the uncluttered look of the single cable and my audio sounded better, but this picture flickering is annoying. Anyone know what might cause this?


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## KurtBJC

It certainly could be your cable, but that's unlikely; more likely, the HDMI interface on your source or your display is responsible. If that's the case, it won't matter what HDMI cable you replace it with.


Thanks,


Kurt
Blue Jeans Cable


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## Davinleeds

I had an issue like this and learned spares are good.

Try it with another source if you can and try reversing the connections.

If this is the first time you've connected by hdmi, trying another cable will help determine if it's the cable or connection.


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## Doc99

I will try another cable. There is really no direction to HDMI cables correct? Oddly, I have found that my component cables have a slightly better picture with my SD stations. I found the flicker problem was happening on SD stations, but not on the HD stations.


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## srobak

Unless your HDMI cable is moving around - that is not the source of your problem. It is digital signaling - it either works or it doesn't. You could use paperclips and get a perfect quality picture and audio.


As Kurt said - it is likely the interface on one end or the other. Try using a different HDMI source over the same cable - if you still experience problems, then it is on your display. If not - then it is the component you had hooked up previously.


Side note - not only HDMI cables uni-directional, ALL cables are - digital, analog, or otherwise.


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## Doc99

The HDMI cable was hooked up to a HD STB, and the problem seems more prevelant on certain SD stations. At first I thought it was the broadcast, or my Samsung plasma, but then the component cables had no problem. I would assume that if it only occurs on certain stations and not others, then it can't be a defective cable.


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## ChrisWiggles




> Quote:
> Originally Posted by *srobak* /forum/post/14431484
> 
> 
> Unless your HDMI cable is moving around - that is not the source of your problem. It is digital signaling - it either works or it doesn't. You could use paperclips and get a perfect quality picture and audio.



Good luck using paper clips and trying to pass uncompressed high definition video and audio!



> Quote:
> As Kurt said - it is likely the interface on one end or the other. Try using a different HDMI source over the same cable - if you still experience problems, then it is on your display. If not - then it is the component you had hooked up previously.
> 
> 
> Side note - not only HDMI cables uni-directional, ALL cables are - digital, analog, or otherwise.



They do not operate unidirectionally, nor do all cables other than HDMI. HDMI communicates (and it must for it even to authenticate and work) between the devices. You typed and posted your response using the internet, undoubtedly connected using cables that are not at all 'uni-directional.'


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## ChrisWiggles




> Quote:
> Originally Posted by *Doc99* /forum/post/14422659
> 
> 
> I purchased an inexpensive HDMI cable from Monoprice, and since I connected it, there has been a flickering on the screen. the image will jutter for a second then stop. It will come and go. I switched back the component cables, and the image is normal. I am now wondering since it is the HDMI cable, should I return it and buy a better quality cable, or is this a common problem that is inherent in HDMI cables? I like the uncluttered look of the single cable and my audio sounded better, but this picture flickering is annoying. Anyone know what might cause this?



The way you described this is somewhat odd. I concur with kurt that it doesn't sound like an HDMI cabling issue, nor would it be something inherent with HDMI generally. I would still test, however, by replacing the HDMI cabling with another just to be sure, but most cabling issues show as sparklies, very bad snow, or no picture at all (or all snow, another version of no picture at all). I would be tempted to point also towards the HDMI ins/outs of one of the devices in question, or their digital path somewhere.


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## srobak

Chris - electrons flow freely down any given piece of cable in either direction. This is a fact of physics which is indisputable. As such, I am not going to get into that discussion with you. Shell out gobs of money on directional cables if you want.


And yes - actually - paperclips will work just fine for both HDV and HDA. Try it once.


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## Doc99

I am going to try another cable, and possibly exchange the set top box. To try and explain the picture: It's like when I am viewing the image on the screen, the image will twitch for a second, as if it shifts it's position and goes back. It occurs randomly about every 10 or 20 seconds or so.


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## ChrisWiggles




> Quote:
> Originally Posted by *srobak* /forum/post/14434464
> 
> 
> Chris - electrons flow freely down any given piece of cable in either direction. This is a fact of physics which is indisputable. As such, I am not going to get into that discussion with you. Shell out gobs of money on directional cables if you want.



Absolutely they do. I never claimed otherwise, such a claim is ridiculous. I responded to the claim that HDMI cables were "uni-directional." I don't know how saying explicitly that HDMI communicates both directions between devices can at all be read to say what you interpreted me to say!



> Quote:
> And yes - actually - paperclips will work just fine for both HDV and HDA. Try it once.



The key to this question is over what distance. You can't do this for very far. If you could, this would be quite a miracle, and many a network engineer would love to see how you did this because it would make their jobs much easier. You do realize that HDMI can be pushing up to ~10gbps, and you can't just do that on any piece of conducting material with continuity. You can do that for some things, but not for such high bandwidth situations. That's why HDMI cables often fail. Step it down (WAAAAY down) to paper clips, and you won't be getting very far, maybe the length of the paper clip. If you have your source less than an inch away from your display, then more power to you, but that's pretty hard to do!


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## ChrisWiggles




> Quote:
> Originally Posted by *Doc99* /forum/post/14435252
> 
> 
> I am going to try another cable, and possibly exchange the set top box. To try and explain the picture: It's like when I am viewing the image on the screen, the image will twitch for a second, as if it shifts it's position and goes back. It occurs randomly about every 10 or 20 seconds or so.



Yes, this does not sound like a cabling issue.


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## srobak

Chris> Key word is CABLE. Unhook an HDMI cable, swap ends, plug it back in - everything still works just fine. I was referring to the *cable*... ALL cable... not communications protocol. Protocols have direction - cables do not. And I am a network engineer.










Doc> Seriously - don't waste the coin on another HDMI cable. Try a different source, or try a different display (read: a friend's) with the same cable. Unless the cable is moving, it is either going to work or not work all the time. Digital signaling - there is no in between.


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## ChrisWiggles




> Quote:
> Originally Posted by *srobak* /forum/post/14435894
> 
> 
> Chris> Key word is CABLE. Unhook an HDMI cable, swap ends, plug it back in - everything still works just fine. I was referring to the *cable*... ALL cable... not communications protocol. Protocols have direction - cables do not. And I am a network engineer.
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> I absolutely agree. That's what I said, too.
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> Quote:
> Doc> Seriously - don't waste the coin on another HDMI cable. Try a different source, or try a different display (read: a friend's) with the same cable. Unless the cable is moving, it is either going to work or not work all the time. Digital signaling - there is no in between.
> 
> Click to expand...
> 
> 
> There is a greyzone though, where it's sort of working but you're getting the sparklies. I would still put that more in the "hey it's not working at all!" category, but...
Click to expand...


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## KurtBJC

srobak: I think that your argument with Chris is a simple confusion over a word--I think you two are completely agreed on the underlying subject.


You said that cables are "uni-directional." I think what you meant was that they are not directional at all, but "uni-directional" means that they work in one direction only. You meant, perhaps, to say "omnidirectional" or "bi-directional" or something like that. Chris is arguing with what you said, not with what you actually meant.


This argument reminds me of an incident during WWII. There was a topic which the American and British staffs both felt was urgent and required immediate review and decision, and the British proposed to "table" it. The Americans objected, saying that the matter was important and must not be tabled. The British responded that it was precisely BECAUSE the matter was so important that it must be tabled. This evidently went on for a while, with both parties becoming increasingly frustrated at the other. Then, someone realized that the problem was that in Britain, to "table" something means to put something up for discussion, while in America, to "table" something means to put it on hold and stop discussing it. The parties were actually in complete agreement all along...


Kurt
Blue Jeans Cable


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## synovia




> Quote:
> Originally Posted by *ChrisWiggles* /forum/post/14435743
> 
> 
> 
> The key to this question is over what distance. You can't do this for very far. If you could, this would be quite a miracle, and many a network engineer would love to see how you did this because it would make their jobs much easier. You do realize that HDMI can be pushing up to ~10gbps, and you can't just do that on any piece of conducting material with continuity. You can do that for some things, but not for such high bandwidth situations. That's why HDMI cables often fail. Step it down (WAAAAY down) to paper clips, and you won't be getting very far, maybe the length of the paper clip. If you have your source less than an inch away from your display, then more power to you, but that's pretty hard to do!



Paper clips are a much heavier gauge than your average hdmi cable, so the results may not be as you expect.


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## KurtBJC




> Quote:
> Originally Posted by *synovia* /forum/post/14436728
> 
> 
> Paper clips are a much heavier gauge than your average hdmi cable, so the results may not be as you expect.



What Chris is pointing out here is that transmission line issues, not wire gage, are going to determine whether signal gets through. If it were all about wire gage, it'd be very easy to make very-long-distance HDMI cable: all we'd need to do would be to build little adapter boxes to allow us to go up to whatever AWG we need for the distance. The reason paperclips would do poorly would not be resistance--it would be that a bunch of paperclips would have very, very poor return loss characteristics due to uncontrolled characteristic impedance.


This is why, when you look at something like high-speed data cable, or microwave coax, or anything like that which is supposed to carry extreme high bitrates or RF frequencies, manufacturing tolerances are so important. Little variations in wire or dielectric dimensions can cause tremendous problems.


Now, the retort at this point is often, "digital is digital and if it gets through it gets through." Yes, I would respond, but there is an "if" in there. While digital signals can endure a lot of waveform degradation before there is data loss, when the data loss comes it comes on fast.


Kurt
Blue Jeans Cable


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## ChrisWiggles




> Quote:
> Originally Posted by *synovia* /forum/post/14436728
> 
> 
> Paper clips are a much heavier gauge than your average hdmi cable, so the results may not be as you expect.



Sure. But gauge is not all that matters in this application. In some wire applications it's pretty much all that realistically does(like speaker wire for instance). In this application, many other things matter like impedance and impedance stability, your various crosstalk issues, etc. If it weren't extraodrinarily difficult to get very high-bandwidth signals from point a to point b, believe you me I would be using paper clips everywhere. But sadly, paper clips simply do not suffice in this kind of application. It may work for POTS, but not for data. And HDMI is basically just an ENORMOUS data pipeline. Figure out how to run 10x Gig ethernet down a chain of paperclips, you've earned yourself unimaginable wealth for life!


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## serkanokar

*Menu flickering on and off*

I am having the same problem with my Sony Ubpx800 Blu-ray player and LG OLED 55cp7 TV (using Aveton brand 4K HDMI Cable 6 ft, rated 5 star by over 500 customers on Amazon, feels like a very well constructed HDMI cable).

The strange thing is that the issue happens only when the Blu-ray player ejects the disc but not during playback. I have read about HDMI handshake issue on the internet and all of the complaints seem to relate to constant flickering. In my case, it happens intermmittently and never during playback.

If the issue is with the connection, as most sites seem to suggest, then what is the explanation for the fact that it doesn't happen during playback of the disc. In fact, to resolve the issue, I put the disc back in, start play and let the movie play for a few minutes, then when I press stop and the movie stops, the menu returns to normal (at least it did every time so far; I have only started using this system only 4 days ago).

Does anybody have a suggestion as to what might be causing the issue and if it is the cable connection, how come the issue doesn't present itself during playback? Thanks for your answer in advance.


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