DVI to HDMI problem on EVGA 9500GT

[Ankh]

I recently purchased the EVGA 9500GT in order to output to a HDTV. I use the DVI port along with a DVI->HDMI converter to a 3M HDMI lead. In parallel, I run a 3.5mm audio lead into the back of the TV, to provide the audio.

This setup worked fine under my old 7300GS using DVI->HDMI, but using the EVGA 9500GT, the TV is no longer outputting the sound. In addition, the TV is generating 'static clicks' over it's speakers with the audio lead plugged / unplugged, suggesting the noise is coming over the DVI->HDMI lead.

I've used headphones from the PC to confirm the sound is coming out of the headphone socket OK, so the only conclusion I can come to is that the 'static clicks' being generated over the DVI->HDMI output is causing the TV to ignore the 3.5mm audio lead input in favour of this false 'HDMI' audio signal.

Has anyone got DVI-HDMI working with the above product?

Cheers,

Rich.

[MarkG]

I had the same problem on my system. Drivers newer than 169.12 tell the TV to expect audio even if the output is DVI. You can either use older drivers, or on my TV, you can change a setting to always use the analog input, and ignore audio from HDMI.

Mark

[Ankh]

OK, thanks for that - have installed 169.09 and will test when I get a moment.
Where did you read about this workaround? Does it just affect dual-link DVI ports, since driver 173.* works OK on my non-dual-link 7300GS DVI?

Cheers,

Rich.

[Ankh]

OK, get audio with 169.09, but horrendous flickering too - will have to check 9500GT compat with that release.

[Tr1cK]

AFAIK 9500GT was added to the most recent releases. Mileage may vary with older drivers.

[Ankh]

OK, have resolved this thanks to comments from MarkG.

I had to create a custom EDID and force the Linux Drivers to use this instead of reading it from the TV, using :

Option "CustomEDID" "DFP-0:/etc/X11/samsung.bin"

I got the TV EDID dump from the Xorg.log, amputated the Extension Block data (anything after byte 127, 0 base), reset the Extension Block count to zero (byte 126) and incremented the checksum by 1 (byte 127) and, tada, the 9500GT now doesn't send the audio over DVI, meaning the TV now plays back the RCA audio.

Cheers,

Rich.

//told you I was hardcore

[bram]

Ah... the custom EDID sounds interesting.
I am going to try this. (Although there was no EDID data in my Xorg.0.log file)
Thanks for posting.

[jsumners]

So you are saying the DVI->HDMI cable I bought today isn't going to fix my problem[1]. Just great. They need to provide some way to turn off this broken feature.

[1] -- http://www.nvnews.net/vbulletin/showthread.php?t=119420

[bram]

Removing the extended block works like a charm!
Thanks a million!

[jsumners]

Thank you for the instructions on how to solve this problem. It is so annoying that this has to be done, but at least it works.

[Ankh]

Glad to have been able to help.

The Wikipedia article on EDID was key to generating the override file, so is a good place to reference if people are stuck.

[AaronP]

Thanks for reporting this, guys. I'll try to look into it soon.