Black screen, works on VGA to monitor but not on VGA to TV
 

Hello,

I have this very frustrating problem... I'm trying to build a Linux-based HTPC (Home Theatre PC). I'm running Ubuntu 9.04 Jaunty as the operating system, and it works fine when I have it connected to my 17" Samsung monitor.

However, when I connect the HTPC to the TV via VGA I get a black screen after "startx" (I can access the console through recovery mode though). Ubuntu is running gnome, so I guess it's a gnome related problem?

I would have thought it was a problem with the drivers to graphics card, but since it's working on my 17" monitor I've ruled that out. The TVs resolution is 1024x768.

What can be causing this? Apperently there's some difference between my monitor and my TV (forgetting the fact that it is indeed a TV, not a monitor), but what?

I've previously run Windows on the same hardware without problems, and thought I should give Linux a shot. It doesn't look good...

Is there any log for startx I could check? Any information anywhere that could help with the troubleshooting?

(I posted about the same problem at the Ubuntu forum, but only about 20 views and no replies. Here it is: http://ubuntuforums.org/showthread.php?t=1200868)

Thanks in advance!

Have you tried Mythtv? Ubuntu do their own version "if that's the right term". Its called Mythbuntu and they have there own forum you will probably get some answers there.

No, I haven't. But this is just a normal desktop installation, it shouldn't depend on the dist. I mean, it SHOULD work =)

A friend is running the same installation to a HTPC, but connected to a projector instead.

I suggest looking into the xorg.conf options pertaining to TV-out signals.
It *might* depend on what video card/driver you are using, but if your card/driver are not detecting that it is connected to a TV, it may be sending the wrong type of signal.

You can specify that the connected device is a TV, and to send NTSC, PAL, or other TV signal formats.

The man page for your driver would be a good place to look; I know the nVidia man page has LOADS of options, and explains how/when to use the TV-out options.

Sasha

But shouldn't my TV act as a monitor? How can I see what drivers I'm using, on my clean install the /etc/X11/xorg.conf is empty!

The TV should act like a monitor, generally speaking, yes. However, it IS a TV after all, not a monitor, right?
TV's usually do not adhere to the same signal standards as monitors do.

The X log is usually located at /var/log/xorg.0.log and the '0' in the middle will be whatever display is being used when creating the log (usually it's 0 in most installations/circumstances)

Now.. An empty xorg.conf file? I don't know what to tell you there. AFAIK 9.04 still uses an X server which likes to have a xorg.conf file. I haven't a clue how you otherwise configure the video settings. If I'm missing something on this front, I'd like to be enlightened by someone though.

FWIW, please post the output of `glxinfo | grep OpenGL` and the output from `lspci`

Thanks for the tips!

I found out that xorg.conf is replaced by xrandr in Ubuntu. I managed to get the TV working by first booting with my normal monitor, and then connecting the TV when in gnome. I could then disconnect the monitor without problems. However, after a reboot I'm back at square one. Is there any way to save the configuration from xrandr to xorg.conf?

I'm not sure how to save xrandr settings to xorg.conf. However, on my desktop (KDE) there is a little gadget (a GUI tool) for xrandr, which I myself have never used because I don't have xrandr enabled, but which I would think can save settings *somewhere* for re-activation on reboot. Maybe if you have such an xrandr tool, it will save the settings?

Sorry I can't help more, but I am going to ask the moderator of this forum that your thread be moved to another forum, maybe 'Ubuntu' or 'Linux - Desktop', so that it might get better exposure to others who are using the same type of setup and can maybe help further.

Sasha

What video card do you have ?

Also, you're saying that you're connecting to the TV with one of these:
http://www.mtsystems.ca/products_pictures/168/2.jpg

and without any other adapters ?

Moved: This thread is more suitable in <Ubuntu> and has been moved accordingly to help your thread/question get the exposure it deserves.

Nvm, solved it...

Just kidding =) I'll explain:

First, thanks for the input everyone!

I have a ATI Radeon 9250, and yes, I'm using that cable without any adapter. The TV has a VGA input.

What I did was I started Ubuntu with my 17" monitor, and then tried different xrandr commands until I got the TV working. What I came up with was:

Now I needed a way to run this command at start up. I googled and found a start script for gdm at /etc/gdm/Init/Default. I added the line there, and it worked!

Excellent! Now you can mark this thread [SOLVED]

Sasha

Ehm... how?

Check 'Thread Tools' at the top :)

Sasha

Aha, thanks, done =)