4870 HDMI output issue

D

Ducay

Limp Gawd
Joined
Sep 24, 2004
Messages
336
Hey all,

This is a different issue than your usual "I can't get sound out of my radeon's HDMI output".

I have a HD4870 hooked up to LCD TV via HDMI. All was well and it was working fine and dandy. Today I got a new LCD TV (A 32" RCA to be exact) and now there is no sound. I think the issue lies because the TV and Catalyst Control Centre are seeing it as a DVI connection and not HDMI.
So when I say that, I mean Catalyst Control Centre is listing the TV as a "Digital Panel DVI instead of a HDMI TV as it was with the previous TV. Im not sure how to get it to output as HDMI again instead of your regular DVI.

Just to note, nothing else was changed except the tv, nothing on the computer changed in terms of wiring etc.

Thanks!
 
Maybe try all the HDMI ports on the TV. Some TV's/AMP's HDMI ports vary for some reason or another. I know I had to try the four ports on my AMP to get one which works with my 4870 (similar sound issue).


Edit: By "AMP" I mean receiver.
 
I've tried both of the HDMI ports on the TV.

Both are labelled as
"HDMI / DVI" and share 1 set of RCA inputs for sound if using DVI to HDMI connection.

I dont want to use the RCA inputs for sound from my PC, Im looking to keep the audio coming over HDMI.


And no, I cant find any option on the TV.
I think it has to do with how the PC is recognizing the TV as a DVI connection instead of an HDMI one, even though Im still using the ATI dVi-HDMI connector.
 
Are you sure that your tv actually supports audio over HDMI? The fact that it has a set of rca inputs for sound while using hdmi sounds like it might not...

Do you have some other hdmi equipment you could use with the tv to see if sound works?
 
The TV does HDMI sounds fine on my XBOX360 (through both HDMI ports)

If only there is a way to tell Catalyst Control Centre that the attached device is not a DVI display, but a HDMI HDTV
 
I feel like its an EDID issue similar to the issue some people have with HDMI through a stereo reciever.

Ive tried a few things, but I think I need a way to edit the EDID (or just disable it) so CCC defaults back to HDMI output (with sound).
 
I searched a bit more and a couple of things I've read were talking about forcing "true" tv resolutions to the TV. That if the tv is thinking it's not getting a real 720p or 1080p signal it just ignores sound.

If it's available in the CCC you could try to force some of the resolutions in the "HDTV support" tab (not sure if it's there when in DVI mode though...)

Also, do you have a model # for the RCA maybe there's some information about how the TV handles HDMI somewhere.
 
The model is an RCA L32HD31

I will do some more work on it after I finish cooking dinner here. and will report back on your suggestions Druneau
 
Does the "ATI audio device/ High Definition audio device" get activated and no sound comes out of the TV. Or does the HDMI audio device has a red x and won't event enable itself on the PC?.

When I was having issues with my receiver I had tried with the ATI drivers and the Realtek drivers. They would give me different scenarios. With the ATI Drivers the sound device would be enabled, but no sound would come out. With the realtek drivers the device would be disabled with a red x.

I had also read about some 48xx ATI Cards having audio through only one of the DVI ports. But since it was working before then I don't see this being part of the problem.
 
Few answers:

-HDMI audio working fine; if I set it as 'Primary Device' I can see things being played; plus it was working fine before I swapped TVs.

Im still set on it being an EDID issue of sorts as the TV is telling the computer that its a DVI monitor; and showing up as such in CCC.

What Id like to do, is somehow disable or override the monitors instructions. It shows up in the device manager as a 'Generic PnP Monitor'
 
SOLVED:

Well, its more of a workaround than a real solution.

What I ended up doing was taking someone's EDID edited LCD device driver, and updating my LCD TV's driver with that one. Sure, my TV registers as a Samsung now, but at least the HDMI sound is working.

EDID driver and idea came from AVS Forum, there was a large topic on a silimar EDID issue with HDMI

http://www.avsforum.com/avs-vb/showthread.php?t=1091403

Thanks all
 
You must log in or register to reply here.
Back
Top