While installing Mythbuntu based on Gutsy Gibbon, version 7,10, I had some trouble switching from onboard video to a PCIe videocard. Below is a detailed description of the problem and the steps taken to fix it. I hope this helps others.
I am building a Mythbuntu system using a motherboard (Foxconn 6150K8MA-8EKRS) with onboard video. The onboard video has an analog D connector which works with just about any monitor on the market. Mythbuntu recognized the onboard video and worked well. Because the onboard video is an nvidia 6150 GPU chip, the driver that worked initially was the opensource nv obtained from the Synaptic Package Manager.
Using the onboard analog video is okay for watching video on a computer monitor, but I want to output video to a TV. Because my amplifier/TV has DVI, HDMI, and component inputs, all I need is a video card with DVI, HDMI and/or component out. Because the motherboard has a PCIe slot, I purchased a PCIe (16x) Nvidia GeForce 8400 GS video card that has analog, DVI and component out.
CHECK THE BIOS
Before installing this video card, I had to check the BIOS setting and made sure that the onboard video was set to initialize the PCIe first on boot up.
Note: Some motherboard might require the onboard be disabled. Because each BIOS is different, it is not possible to give detailed instructions on how to do this for others. It is recommended to look for either Plug-n-Play or Integrated Peripherals in the BIOS.
I installed the PCIe video card and connected my monitor to the analog output to the PCIe video card. I rebooted the machine and there was just a black screen all the way through the entire boot up. Nothing appeared what-so-ever at any time.
PROBABLE CAUSE FOR PROBLEM #1
Because nothing appeared on the screen at all during boot up, suggested that the video was not directed to the analog out on the PCIe video card.
FIX FOR PROBLEM #1
I connected my monitor to the DVI out on the PCIe video card and I rebooted. I saw the normal BIOS POST screen, grub screen, and Mythbuntu splash screen (with blue bar) on boot up.
When booting up, I was able to see the normal BIOS POST and grub screens, as well as the Mythbuntu splash screen with the blue bar moving across.
Unfortunately, the XFCE desktop screen never showed. I was back to a black screen.
PROBABLE CAUSE FOR PROBLEM #2
Because I could see the BIOS POST, grub and Mythbuntu splash screens suggested that the hardware could see the PCIe card and the problem was in the Mythbuntu software.
Time to check which video device Mythbuntu was using for video.
- When Grub prompt appears (count down to 0), pressed the Esc key.
- Selected option #2 (recovery mode).
- At the command prompt, enter the following command
- Scrolled down to the Section "Device" and looked at the video card setting and found the following:
Identifier "Generic Video Card"
Boardname "nVidia Corporation C51PV [GeForce 6150] (rev a2)"
Wholla! The fact that the boardname had [GeForce 6150] told me that Mythbuntu was trying to use the onboard video to display the desktop user interface.
FIX FOR PROBLEM #2
The fix was to update the xorg.conf file with the correct video card device. Mythbuntu comes with a utility called 'dpkg-reconfigure' that will ask questions and modify the the xorg.conf file; however, before I could use this utility I needed to first determine the BusID of the PCIe video card.
DETERMINE BUSID OF PCIe VIDEO CARD
- Launch a terminal (Applications --> Accessories --> Terminal)
- Enter the following command
Note: The above command will display video pci devices.lspci -x | grep -i "vga\|display"
- Review PCI device output
PCI:00:05.0 nVidia Corporation C51PV [GeForce 6150] (rev a2)
PCI:03:00.0 nVidia Corporation GeForce 8400 GS (rev a1)
The output provided the BUSID of the PCIe GeForce 8400 GS video card, which was PCI:03:00.0.
To update the xorg.conf file with the BUSID of the PCIe video card, execute the following command in a terminal.
This utility will ask questions and configure video, keyboard and monitor settings.dpkg-reconfigure xserver-xorg
For video, the following three questions will be asked.
- Device Name
For my system, I entered the following for each...
- Driver - nv
- Device Name - nVidia Corporation GeForce 8400 GS (rev a1)
- BusID - PCI:3:0:0
Notice that the BusID entered was slightly different from the way it was displayed with the lspci command. This is because I entered the BusID in hex mode and the lspci was not. To change to hex, I simply replaced the periods (.) with semicolons ( : ) and removed the extra zeros (0).
For the keyboard and monitor settings, I accepted the defaults.
The dpkg-reconfigure utility ended by asking to save and over write the current xorg.conf file (it automatically created a backup), which I did.
After updating the xorg.conf file, I rebooted and Mythbuntu booted up completely to the XFCE desktop.
I hope this helps others.