# Audio Problem Paired with DP to HDMI Connection



## BerretSO4 (Jul 22, 2004)

Hello all!

I have a Lenovo X200 Tablet with the Ultrabase, fully spec'd, and was tinkering around with what I could do to use my Samsung HP-T5054 Plasma 50" as an external monitor and speaker set. Let me know if you need more hardware spec.

I have two current options for getting the signal from my laptop to the TV; both have the same issue:

The first is a converter straight from the DP (Display Port) to HDMI 1.3, from which an HDMI 1.3 cable carries the video signal to the TV's HDMI-1 port. For this version, and possibly even in today's market, DisplayPort (DP) does not stream audio with its video signal, so I paired it with a stereo 1/8" jack line from the laptop and attached it to the R/L (Red/White) IN paired with the HDMI-1 Input on the TV. The video, after tinkering, came in at the proper resolution and clear as a bell. The audio, however, did not come in at all. The TV received no audio, and yet the video was clear. At this point, it seemed like the video signal was transferring some sort of audio carrier, or was telling the HDMI to send a positive audio data track that said "Hey, audio's on the way", with no actual audio on the way, which must have convinced the TV to not accept the available Analog R/L in.

Knowing this, and knowing that if I detached the 1/8" from my laptop I would hear the internal speakers unmute (this implies that audio is indeed going out when the line is attached), I sought a Mac to address whether my laptop was the problem.

The Mac had a different setup, which I emulated soon after witnessing its success: Mini-DP to DVI-D, then DVI-D to HDMI 1.3, then HDMI 1.3 to TV, paired with an 1/8" audio line split to R/L and attached to the same place on the TV as before. Indeed, the Mac's audio signal and video signal both came through the TV clear as a bell. I decided at this point that the answer was certainly in the primary difference in methods: conversion to DVI.

Therefore, I bought the correct adapters to go from DP to DVI-D, then DVI-D to HDMI 1.3, then HDMI to the TV. The video was much better at many resolutions, however the issue still arose that the R/L on the TV was not receiving any audio, as it had with the Mac. The audio from the laptop still played through the line (I tested it going to other powered speakers while it was outputting video to the TV), but would never be accepted by the TV. I have researched the TV as much as possible and tried this setup, along with the Mac as a control, on another Samsung of a different model, having the exact same results. There are no settings that I can see on the TV that address forcing the audio to come from the R/L paired with HDMI-1, instead of expecting it through the HDMI. The TV simply decides automatically once it receives the HDMI source.

The problem must lie in the DP on my laptop, no? I am thoroughly confused - why has converting the signal to DVI, THEN to HDMI, not fixed the problem of the TV "thinking" that the audio signal should not be accepted by the coupled R/L, when it did accept it on the Mac with the same configuration?

I understand this is a fairly specific and complex situation, but I'll be happy to try anything to figure this out. It is very frustrating considering the cost of adapters and time alone. You guys and girls are smart! Lay it on me!

Thanks in advance for your help,
BerretSO4


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## etaf (Oct 2, 2003)

My first reaction is that the TV is blocking the audio signal from the lenovo laptop for some reason

What I would do - is this - you know the MAC works - I would set the MAC up and have it working on vid and audio
Then I would just connect up the audio from the lenovo an see if that comes through.
Then you at least know the audio is working on the Lenovo.

I would then do the opposite 
TV signal from the Lenovo X200 Tablet
and audio from the MAC
IF this works - Then you know the Audio from the Lenovo is not getting through to the TV - even though the TV will accept an audio signal. And my first reaction is wrong

post back those results


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## BerretSO4 (Jul 22, 2004)

Thank you for the good test ideas. I have done both and the results:

1. When the Mac is connected via video, the Lenovo's audio does indeed go through.

2. When the Lenovo's video is connected, the Mac's audio does not go through.

This is evidence that the audio rejection is isolated to the presence of the Lenovo's Display Port. So that still leaves me at square one for now, I suppose.


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## etaf (Oct 2, 2003)

> So that still leaves me at square one for now, I suppose.


well a little further forward 
You have confirmed that the Lenevo's Video is blocking the Audio. 
So we just need to work out why the Video signal is switching the TV OFF

On my Sony - I have under audio - an selection for HDMI Audio 
So can you turn off the Audio in HDMI on the Lenovo
Mine is under control panel - Audio

OR

Why is the TV not picking up the HDMI Audio from the Lenovo


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## BerretSO4 (Jul 22, 2004)

This is what I was thinking might be the solution. However, my sound devices only include "Speakers" and "Headphones", with no HDMI option, even when the display is attached to the TV via the cable I described, at least not in any control interface I have found. I do have two more applications that go along with my onboard audio card and have checked through every nook and cranny for HDMI or Display Port audio options and have found none.

The connection on the Lenovo is Display Port, the version of which I am unaware. The laptop was manufactured around January 2009, so I doubt, myself, that this was when Display Port was supporting audio with its video stream, but I cannot back this up with research. I seem to recall a Lenovo representative stating that the audio/visual capability would not be available in DP until the new "calpella" generation chipset is released, which as I understand has as of yet to occur. 

If it is the DP without audio, then there shouldn't be any audio source mixing things up, much less a faulty one.... If it is the DP with audio, then the audio could be lost or corrupted in translation, or is in fact muted, but considering the direct adapter from DP to HDMI did not show this possibility, it is doubtful.

Is there possibly an Environment Variable that might force Vista to display a DP sound controller? My problem with this situation is that it makes very little logical sense considering the circumstances.


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## etaf (Oct 2, 2003)

have a read here
http://forums.lenovo.com/t5/W-Serie...o-HDMI-with-audio/m-p/75988/message-uid/75988

http://forum.lenovo.com/t5/W-Series...9;jsessionid=C060E8A92AA2FBDCE6AD2E52F0895F68

http://forum.notebookreview.com/showthread.php?t=293049

http://www.thinkpads.com/forum/viewtopic.php?f=43&t=69912

it appears to be a hardware issue on sound.....

although like you - I cant make sense of why you cannot use the seperate audio onto the TV as you say the signal does it appear at the headphone jack output on the laptop, and so should be available on the TV and we know the TV will accept an audio signal from the MAC with the Lenovo connected

Are you sure you are getting an audio signal from the laptop when connected to TV


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## BerretSO4 (Jul 22, 2004)

> and we know the TV will accept an audio signal from the MAC with the Lenovo connected


I may have mistyped - I do not get an audio signal from the Mac or any other audio device if the Lenovo's video is connected. I do get a feed still from the analog headphone jack of the Lenovo, however, but it is NOT accepted by the Samsung.

That should clear that up, I hope.

Yes, the calpella chipset it seems will include DP + Audio support, and this chipset does not, however the question remains... why does the Samsung TV not accept audio from my Lenovo, or any other device for that matter, while I have the Lenovo's DP connected? Even when the DP is converted to DVI before HDMI? Which, as I can see now, is only a redundant way to be sure that no audio is being transmitted.

I do have some more information, and this will get extremely technical so anyone with electrical experience feel free to chime in:

I have circuit-tested the voltages of the DVI female outputs from the Lenovo and the Mac and compared them pin-by-pin. To be clear, I connected each DP to DVI adapter to the DP port of the respecting laptops while the laptops were powered and did a pin test as compared to the +5v always-on pin. If I'm using the wrong terminology it's because I'm not as knowledgeable in this area.

When testing voltages from the live +5 volt pin, I saw an interesting difference in what the Lenovo was transmitting, when compared to the Mac. All of the pins that were either a ground or -5v feed were the same in position and voltage between the two, but the pins that were lower voltage (on the Mac, +.8v) were remarkably lower on the Lenovo's output (instead, +.078v). The pins different are, when looking at a female DVI-D pin-out diagram, the two left-most columns and the two pins on the bottom right hand corner (next to the analog cross). A pinout diagram can be found here:

http://upload.wikimedia.org/wikipedia/commons/0/03/DVI_pinout.png

As you can see in the photo, the light green and pink pins were those with the voltage change. All other pins were equal. The pin I tested to was Pin 6, which read +5v.

Dear electricians, does this explain in some way why the TV would deny the audio signal when the Lenovo's video is attached (transmitting this lower voltage on those pins)? Note that I do not have a board to test the active connections of the pins. This is only a passive test.


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## etaf (Oct 2, 2003)

> 2. When the Lenovo's video is connected, the Mac's audio does not go through.


Sorry my mistake.......

Well that means that the samsung is blocking the audio, as you say.

I would not be worried about a difference between 0.8 and 0.78 V
Also most likely Digital Signals so need to use a scope.

_
I would use this a good reason to justify a nice sound system for the tv   
_

is there anyway to select audio source from the samsung settings at all?


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## BerretSO4 (Jul 22, 2004)

etaf said:


> Sorry my mistake.......


It's all good!



etaf said:


> Well that means that the samsung is blocking the audio, as you say.
> 
> I would not be worried about a difference between 0.8 and 0.78 V


I doubt it makes a difference according to what you said, but the difference is actually between .8v and *.078v*, not .78v. Seems to be a much larger differential, in case it would actually do anything



etaf said:


> Also most likely Digital Signals so need to use a scope.


Yeah, I don't know the first thing about that. 



etaf said:


> _
> I would use this a good reason to justify a nice sound system for the tv
> _


 _researches sound systems_ - Man, I wish I had the budget.



etaf said:


> is there anyway to select audio source from the samsung settings at all?


I have looked and looked in the Samsung's menus. I even manually upgraded the firmware on the TV, which unfortunately did nothing, and haven't seen a single thing that mentions an option to, say, take the audio input from another source. That option would be a perfect workaround... if only...

I also went ahead and installed Windows 7 x64 and its Lenovo audio and video drivers in order to be fully up to date. (I was planning on 7, this just came at an appropriate time) And there has been no change whatsoever with the problem. I am baffled! It must be a hardware problem with the laptop.

I have a strong feeling that Lenovo could make a quick edit to the video driver that would fix this, but I'm afraid they will have little reason to beyond my simple case. Seems like I'm the only person this has happened to. I might try copying this thread to the Lenovo forums.


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## etaf (Oct 2, 2003)

> I doubt it makes a difference according to what you said, but the difference is actually between .8v and .078v, not .78v. Seems to be a much larger differential, in case it would actually do anything


Now that would be a problem. 
Just depends on what that signal does? and if its a digital signal - so would change from a 1 to a 0 high to low voltage,


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## BerretSO4 (Jul 22, 2004)

I don't know what the pin is, past the link I put above of the pin-out diagram. It is video signal and two clock pins. The diagram is there for specifics. But yeah it is a big differential. Of what data, I know not. Again, this was a passive test.


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