Ubuntu does not recognize HDMI port

Question

I am running Ubuntu (elementary OS) connected to a normal monitor which works fine. I am now trying to connect it to a TV through HDMI port, but the TV is unable get any signal. Please help me out.

Output of: sudo lshw -C display

  *-display               
   description: VGA compatible controller
   product: RS780L [Radeon 3000]
   vendor: Hynix Semiconductor (Hyundai Electronics)
   physical id: 5
   bus info: pci@0000:01:05.0
   version: 00
   width: 32 bits
   clock: 33MHz
   capabilities: pm msi vga_controller bus_master cap_list rom
   configuration: driver=radeon latency=0
   resources: irq:18 memory:d0000000-dfffffff ioport:d000(size=256) memory:feaf0000-feafffff memory:fe900000-fe9fffff

Output of xrandr:

\Screen 0: minimum 320 x 200, current 1366 x 768, maximum 8192 x 8192
VGA-0 connected 1366x768+0+0 (normal left inverted right x axis y axis) 410mm x 230mm
1366x768       59.8*+
1024x768       75.1     60.0  
800x600        75.0     60.3  
640x480        75.0     60.0  
720x400        70.1  
DVI-0 disconnected (normal left inverted right x axis y axis)

xrandr does not show HDMI at all. Is this a problem?

Output of sudo get-edid | parse-edid

parse-edid: parse-edid version 2.0.0
get-edid: get-edid version 2.0.0

Performing real mode VBE call
Interrupt 0x10 ax=0x4f00 bx=0x0 cx=0x0
Function supported
Call successful

VBE version 300
VBE string at 0xc01d0 "ATI ATOMBIOS"

VBE/DDC service about to be called
Report DDC capabilities

Performing real mode VBE call
Interrupt 0x10 ax=0x4f15 bx=0x0 cx=0x0
Function supported
Call successful

Monitor and video card combination does not support DDC1 transfers
Monitor and video card combination supports DDC2 transfers
0 seconds per 128 byte EDID block transfer
Screen is not blanked during DDC transfer

Reading next EDID block

VBE/DDC service about to be called
    Read EDID

    Performing real mode VBE call
    Interrupt 0x10 ax=0x4f15 bx=0x1 cx=0x0
    Function supported
    Call successful

parse-edid: EDID checksum passed.

# EDID version 1 revision 3
Section "Monitor"
# Block type: 2:0 3:ff
# Block type: 2:0 3:fc
Identifier "DELL IN1930"
VendorName "DEL"
ModelName "DELL IN1930"
# Block type: 2:0 3:ff
# Block type: 2:0 3:fc
# Block type: 2:0 3:fd
HorizSync 30-83
VertRefresh 56-75
# Max dot clock (video bandwidth) 90 MHz
# DPMS capabilities: Active off:yes  Suspend:yes  Standby:yes

Mode    "1366x768"  # vfreq 59.790Hz, hfreq 47.712kHz
    DotClock    85.500000
    HTimings    1366 1436 1579 1792
    VTimings    768 771 774 798
    Flags   "+HSync" "+VSync"
EndMode
# Block type: 2:0 3:ff
# Block type: 2:0 3:fc
# Block type: 2:0 3:fd
EndSection

I am unable to understand what needs to be done here. Could you please explain. I still am not sure if my PC sending some output via the HDMI port. Please help!

Solution

If you are trying to do a dual display, look into your "System Settings" for "Screen Display". There is usually a setting for "mirror display" (same thing on both screens) or "extend display" (have your desktop use both screens). On many installations, these don't turn on just by plugging a 2nd screen in.

If this is a single display and you are trying to replace a monitor by a TV, make sure that:

• your TV can handle the resolution and refresh rates that the graphics card is trying to output
• your TV is set to the correct HDMI outout that you've plugged into (my TV has 4, and you can cycle through them using the "input" button on the remote)
• try another HDMI connector on the TV
• make sure your graphics card is sending a signal through HDMI. You may need to edit your xorg.conf file for this, see details here.

Comments

[Danibix]

Did you set up TV to get as input HDMI?

[user283926]

@Danibix TV to receive HDMI input. Disconnected STB to TV HDMI and connected the cable to PC instead.

[Martin Thornton]

Elementary OS questions should be asked over at elementaryos.stackexchange.com

[user283926]

This doesn't seem to be an elementary os question. This is more like a ubuntu / linux problem.

[tlhIngan]

@user283926 Look at your BIOS settings, sometimes HDMI is disabled in the BIOS. And also look at your xorg.conf, often this is where you specify which of multiple outputs you want to use. It is often located at /etc/X11

[Andrea Lazzarotto]

You are using Elementary OS and you think yours is not an Elementary OS question? Besides, Elementary OS is a Linux OS so yeah of course it's a Linux problem.

[Robert Johnstone]

@user283926 can you tell me if you found a solution to this problem as I am having the EXACT same problem

[Robert Johnstone]

I found the solution for this in the end. For me it was to plug the monitor into another machine (Windows) (the monitor then recalibrated) and then plug it back into the laptop and it was re-recognized

[user283926]

I have attached a screenshot above of the display settings. Mirror displays is turned off.