Comcast Moto box, HDMI-DVI and no sound

jnolan · 12-29-2004, 09:02 PM

I'm relatively new to HD, so please bear with me.

I bought a 30" Philips LCD about 6 weeks ago, and at the same time picked up a Comcast Motorola set top box in order to get HD programming. At the time I used the component video connectors and everything worked, but I could only get 480i/p.

Today I bought a Belkin Pure AV DVI-HDMI cable and hooked it up, the HD channels came through in 720p or 1080i and were fantastic, but there was no sound. I attempted to patch the audio out connectors on the set top box to an audio in on the LCD, but without success.

The Comcast tech who came to my house shrugged his shoulders and couldn't do anything. The real problem is that the CV1 input no longer displays any video, although it does have sound. So not only am I not getting sound with the HDMI input, I'm not getting video with the CV input so I'm SOL.

Any ideas on either of these problems?

mfabien · 12-30-2004, 05:07 AM

You say your digital video connection is DVI out to HDMI in.

My TV has audio inputs under the DVI input. With HDMI, in your case, the audio was designed to come in as part of the digital connection in one fitting (HDMI).

With an a/v receiver you would simply connect a digital audio cable (optical or coax) between the STB and the a/v.

Now there are a lot of people using a DVI to HDMI cable and hopefully one will come to this thread and say how they are able to get audio to the TV.

KurtT · 12-30-2004, 07:40 AM

Quote:

Originally Posted by jnolan

I attempted to patch the audio out connectors on the set top box to an audio in on the LCD, but without success.

Do you have the Motorola 6200 series? If so, there are multiple "audio outs". You need to use the ones immediatly to the left of the DVI connection, if you are looking at it from the wrong side, the connector is in the way and they are kinda hard to see. If you done that, and that doesn't work, I'd call Comcast and have them come change out the box.

SesnOfWthr · 12-30-2004, 08:09 AM

This is the same thing I'm dealing with right now. I have two DVI devices, but only one DVI port and one HDMI port.

As mfabien said, it seems the only thing you can do is to use the audio out from the cable box, and send the sound to your sound system. Unless, you have a TV that can pull the audio from one input, and the video from another, that's the only solution, it would seem.

However, do you have any other inputs available for the TV? Perhaps an Dsub hookup, or something? I'm not sure what would happen to the quality of the video using a DVI -> Dsub cable, or if you can even get one, but it may be worth looking into.

EDIT: for the CV input, is it possible you swapped the red wires? Not sure what kind of effect this would have, but it's a "possible".

arty fufkin · 12-30-2004, 08:09 AM

Just remember, the DVI output ONLY outputs VIDEO - as far as outputting audio from your STB to the TV, you should not have to...the TV should have the audio signal/pids from the coax input to the box already....
Or as a previous posted replied, just run optical or digicoax out to a receiver ( for surround sound goodness ) - just make sure that that if you are running a TVGUIDE program guide, that you go into the audio settings and switch it from the default TV setting, to advanced stereo, or matrix stereo.

jnolan · 12-30-2004, 10:08 AM

Okay, that clears up a lot. Here's what I think is happening:

1) the Philips LCD has an HDMI, therefore it is expecting audio along with the video when it senses the HDMI is hot
2) with the above in mind, the LCD ignores every other input when the HDMI is on
3) the STB is DVI therefore it's audio out connectors are live, along with the SPDIF.

Solution:
1) downgrade the HD to 480i/p and use component video
2) use the DVI-HDMI along with an aux sound system that feeds from the SPDIF (better solution even though it does cost me more $$).

thanks for all the help

arty fufkin · 12-30-2004, 10:47 AM

Quote:

Originally Posted by jnolan

Okay, that clears up a lot. Here's what I think is happening:

1) the Philips LCD has an HDMI, therefore it is expecting audio along with the video when it senses the HDMI is hot
2) with the above in mind, the LCD ignores every other input when the HDMI is on
3) the STB is DVI therefore it's audio out connectors are live, along with the SPDIF.

Solution:
1) downgrade the HD to 480i/p and use component video
2) use the DVI-HDMI along with an aux sound system that feeds from the SPDIF (better solution even though it does cost me more $$).

thanks for all the help

I go with solution#2 in my home...
Check the specs on your TV to see if you are correct about the 1st 2 points you mentioned - quite possible it has a function so that you can control the audio source....that'd be a tremendous over site by them if they didn't.

jnolan · 12-30-2004, 12:09 PM

I just got off the phone with Philips customer support. When the LCD is being driven by the HDMI connection, all of the other input are ignored meaning that the only way to get audio with the HDMI connection when you are doing DVI-HDMI conversion is through an A/V receiver.

It is a tremendous oversight by Philips and was acknowledged by the support rep... although admission of error doesn't do me much good.

arty fufkin · 12-30-2004, 03:09 PM

That's complete suckage.

Sry man

12-29-2004, 09:02 PM	#1
jnolan What is HD? Join Date: Dec 2004 Posts: 4	Comcast Moto box, HDMI-DVI and no sound I'm relatively new to HD, so please bear with me. I bought a 30" Philips LCD about 6 weeks ago, and at the same time picked up a Comcast Motorola set top box in order to get HD programming. At the time I used the component video connectors and everything worked, but I could only get 480i/p. Today I bought a Belkin Pure AV DVI-HDMI cable and hooked it up, the HD channels came through in 720p or 1080i and were fantastic, but there was no sound. I attempted to patch the audio out connectors on the set top box to an audio in on the LCD, but without success. The Comcast tech who came to my house shrugged his shoulders and couldn't do anything. The real problem is that the CV1 input no longer displays any video, although it does have sound. So not only am I not getting sound with the HDMI input, I'm not getting video with the CV input so I'm SOL. Any ideas on either of these problems?

12-30-2004, 08:09 AM	#4
SesnOfWthr Not quite a newb anymore Join Date: Nov 2004 Location: Red Sox Nation Posts: 31	This is the same thing I'm dealing with right now. I have two DVI devices, but only one DVI port and one HDMI port. As mfabien said, it seems the only thing you can do is to use the audio out from the cable box, and send the sound to your sound system. Unless, you have a TV that can pull the audio from one input, and the video from another, that's the only solution, it would seem. However, do you have any other inputs available for the TV? Perhaps an Dsub hookup, or something? I'm not sure what would happen to the quality of the video using a DVI -> Dsub cable, or if you can even get one, but it may be worth looking into. EDIT: for the CV input, is it possible you swapped the red wires? Not sure what kind of effect this would have, but it's a "possible". __________________ Still celebrating the World Series...... The Sammy DLP is here, and .... woohoo!! Last edited by SesnOfWthr; 12-30-2004 at 08:34 AM.

12-30-2004, 05:07 AM	#2
mfabien High Definition is the definition of life. Join Date: Aug 2004 Location: Montreal Posts: 1,087	You say your digital video connection is DVI out to HDMI in. My TV has audio inputs under the DVI input. With HDMI, in your case, the audio was designed to come in as part of the digital connection in one fitting (HDMI). With an a/v receiver you would simply connect a digital audio cable (optical or coax) between the STB and the a/v. Now there are a lot of people using a DVI to HDMI cable and hopefully one will come to this thread and say how they are able to get audio to the TV. __________________ Samsung LN52B750, SA8300HD, Energy speakers, Yamaha RX-V540, SVS PB12-ISD, Harmony 880, HD-A1, BDP-1400, Oppo DV-970HD, Zektor HDS4.1

12-30-2004, 08:09 AM	#5
arty fufkin A couch and an HDTV to go please. Join Date: Dec 2004 Posts: 14	Just remember, the DVI output ONLY outputs VIDEO - as far as outputting audio from your STB to the TV, you should not have to...the TV should have the audio signal/pids from the coax input to the box already.... Or as a previous posted replied, just run optical or digicoax out to a receiver ( for surround sound goodness ) - just make sure that that if you are running a TVGUIDE program guide, that you go into the audio settings and switch it from the default TV setting, to advanced stereo, or matrix stereo.

12-30-2004, 10:08 AM	#6
jnolan What is HD? Join Date: Dec 2004 Posts: 4	Okay, that clears up a lot. Here's what I think is happening: 1) the Philips LCD has an HDMI, therefore it is expecting audio along with the video when it senses the HDMI is hot 2) with the above in mind, the LCD ignores every other input when the HDMI is on 3) the STB is DVI therefore it's audio out connectors are live, along with the SPDIF. Solution: 1) downgrade the HD to 480i/p and use component video 2) use the DVI-HDMI along with an aux sound system that feeds from the SPDIF (better solution even though it does cost me more $$). thanks for all the help

12-30-2004, 12:09 PM	#8
jnolan What is HD? Join Date: Dec 2004 Posts: 4	I just got off the phone with Philips customer support. When the LCD is being driven by the HDMI connection, all of the other input are ignored meaning that the only way to get audio with the HDMI connection when you are doing DVI-HDMI conversion is through an A/V receiver. It is a tremendous oversight by Philips and was acknowledged by the support rep... although admission of error doesn't do me much good.

12-30-2004, 03:09 PM	#9
arty fufkin A couch and an HDTV to go please. Join Date: Dec 2004 Posts: 14	That's complete suckage. Sry man