(SOLVED) LG Plasma Displays Kubuntu But Not MCE

[twodogs]

I've got my MCE setup running well on my workbench connected to a digital monitor. This afternoon I tried to get it to work with my LG DU-42PX12X plasma TV (which has a DVI connection and is made to work with a PC). I can watch Kubuntu boot, but when MCE starts the screen goes blank. I figured that this was a resolution problem that could be fixed with the A/V wizard. I reconnected the PC monitor and rebooted using the shift key to start the wizard. My TV manual says that the optimum setting with a PC is 1024x768, 60Hz. I selected that setting on the wizard and my monitor displayed it correctly. I then unplugged the DVI cable to the monitor and plugged in the DVI from the TV and the screen was again blank.
I know my MCE installation is good. I know my LG plasma and DVI cable are good because they display Kubuntu as it boots. Does anyone know what might be the problem?

John

[merkur2k]

the DVI output and the VGA output are two separate things. if you tell it to use the VGA output in avwizard, it will continue using that output even though you have connected a DVI cable.
see this wiki page http://wiki.linuxmce.org/index.php/AV_Wizard_Step_by_Step particularly section 2.

[DragonK]

Hi,

Does your graphics card and LG Plasma have s-video ports?

Karel

[purps]

Just connect everything up how you want it, start the AVWizard, and when you get the blank screen press "1" on your keyboard and wait a sec. If that doesn't work, wait a few minutes, and try "2". And so on.

Cheers,
Matt.

[twodogs]

My test monitor is HDMI so I know about the initial blank screen until you press 1. That works with the monitor but not the TV. I even tried connecting the monitor, pressing 1 to get the wizard, then swapping the monitor with the TV to see if the wizard would even show up. The TV would always display "No Input".
I found this thread that talks about an EDID problem.

http://forum.linuxmce.org/index.php?topic=9011.0

I decided it was worth a try so I modified xorg.conf Under Section "Screen"

Code Select Expand

Subsection "Device"
Modes "1024x768" #this might be different for you, but it should match the modeline name in the monitor section
EndSubSection

The above resolution is native for my plasma (1024x768, 60Hz). After I made this change and rebooted, I could see the wizard on the TV for the first time. However, setting the above resolution in the wizard resulted in a "No Input". I started to try all the resolutions and discovered that 480p worked.
I'm still researching this problem and would appreciate input. I'd like to get things running at the full native resolution of the screen. Maybe I have a timing issue, but I don't know enough about xorg.conf to specify 60Hz.

[purps]

Don't you specify the refresh with _60 or whatever? So in your case...

Code Select Expand

1024x768_60

Please don't shout at me if that ruins everything; I assume you're backing xorg.conf up each time anyway right?

Cheers,
Matt.

[daballiemo]

I have had a PX11 for a number of years working on DVI but I had to throw in a adapter I ordered in the USA. Combination of MB (asus M2NPV-VM and LG giving back wrong edid data caused the DVI port not to work. After connecting the DVI detective (Gefen) my DVI worked without any hassle. You  see the splash because at that time still both VGA and DVI are driven.

rgds

Han

[twodogs]

I Googled edid.bin and see references to bugs and messed up resolutions with NVIDIA drivers. It seems that a few people have solved this problem by manually generating a valid edid.bin file, then manually forcing xorg to use this.

http://forums.nvidia.com/index.php?showtopic=73027

I think I'll give this a try on Monday. All else fails I might go looking for a DVI Detective.

John

[twodogs]

This turned out to be more involved than I thought, but Purps was right - I needed to specify the refresh rate. I put the full story in a long post in a new thread.

http://forum.linuxmce.org/index.php?topic=11407.0