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I'm having a problem while I connect HDMI cable to my monitor. I'm dual booting Windows 10 64 bit and Ubuntu 16.04 64 bit. When I turn on my system with HDMI connected, monitor says no signal, until I reach the login screen of default OS.No issues in display after login. But I'm not getting GRUB menu to select OS. My GPU is Nvidia Geforce GT630. When I connect VGA cable, no such issues occur. Please help me solve this problem. Pardon if this is a duplicate question.

La Corazón
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  • Do you have any other cables connected to the video card other than just the HDMI? Extra cables can cause confusion to the video card. – Terrance Dec 11 '16 at 04:39
  • No. I unplugged VGA cable and tried. Same thing happens. – La Corazón Dec 11 '16 at 04:40
  • Interesting. I had the same issue, even with a second monitor attached, and my second monitor would show the grub and BIOS screens. My HDMI would not show anything until the OS was up. I have heard that having straight HDMI should work. Maybe I am the wrong person to answer this for you. Hopefully someone else might know better than me. – Terrance Dec 11 '16 at 04:42
  • Ok Mr. Terrance. Thanks for your reply. BTW, I only have a single monitor. It's actually a LCD TV. I changed display mode to HDMI before turning on the system. – La Corazón Dec 11 '16 at 04:44
  • Might need to try the VGA cable if you can and check your BIOS if it allows for default of HDMI. https://askubuntu.com/questions/62019/how-to-activate-hdmi-as-my-default-output-starting-from-bios-grub-gdm-and-de – Terrance Dec 11 '16 at 04:48
  • I checked BIOS settings, but it has no such option to set HDMI as default – La Corazón Dec 16 '16 at 16:48

2 Answers2

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Since it will not show you your grub screen at startup, there is something you can do to select what OS you want to boot to, but it will require booting to your Ubuntu first.

You can use grub-reboot to select the next one time boot.

First, make sure the default is selected for grub:

:~$ grep "GRUB_DEFAULT" /etc/default/grub
GRUB_DEFAULT=0

Here you can see that GRUB_DEFAULT is set for the first entry since it starts counting at 0.

Next, view all your entries that you have in your grub menu by using grep -i "menuentry '" /boot/grub/grub.cfg:

:~$ grep -i "menuentry '" /boot/grub/grub.cfg
menuentry 'Ubuntu' --class ubuntu --class gnu-linux --class gnu --class os $menuentry_id_option 'gnulinux-simple-9e4539a5-7229-424e-aa91-60ab1417e6f1' {
    menuentry 'Ubuntu, with Linux 4.4.0-53-generic' --class ubuntu --class gnu-linux --class gnu --class os $menuentry_id_option 'gnulinux-4.4.0-53-generic-advanced-9e4539a5-7229-424e-aa91-60ab1417e6f1' {
    menuentry 'Ubuntu, with Linux 4.4.0-53-generic (upstart)' --class ubuntu --class gnu-linux --class gnu --class os $menuentry_id_option 'gnulinux-4.4.0-53-generic-init-upstart-9e4539a5-7229-424e-aa91-60ab1417e6f1' {
    menuentry 'Ubuntu, with Linux 4.4.0-53-generic (recovery mode)' --class ubuntu --class gnu-linux --class gnu --class os $menuentry_id_option 'gnulinux-4.4.0-53-generic-recovery-9e4539a5-7229-424e-aa91-60ab1417e6f1' {
    menuentry 'Ubuntu, with Linux 4.4.0-52-generic' --class ubuntu --class gnu-linux --class gnu --class os $menuentry_id_option 'gnulinux-4.4.0-52-generic-advanced-9e4539a5-7229-424e-aa91-60ab1417e6f1' {
    menuentry 'Ubuntu, with Linux 4.4.0-52-generic (upstart)' --class ubuntu --class gnu-linux --class gnu --class os $menuentry_id_option 'gnulinux-4.4.0-52-generic-init-upstart-9e4539a5-7229-424e-aa91-60ab1417e6f1' {
    menuentry 'Ubuntu, with Linux 4.4.0-52-generic (recovery mode)' --class ubuntu --class gnu-linux --class gnu --class os $menuentry_id_option 'gnulinux-4.4.0-52-generic-recovery-9e4539a5-7229-424e-aa91-60ab1417e6f1' {
menuentry 'Memory test (memtest86+)' {
menuentry 'Memory test (memtest86+, serial console 115200)' {
menuentry 'Windows 10 (loader) (on /dev/sdh1)' --class windows --class os $menuentry_id_option 'osprober-chain-E2CAE74ACAE71A15' {

See the entry you want to have your system boot to by default for the next boot only. Here we are going to use my Windows 10 entry. We will set it up using grub-reboot command:

:~$ sudo grub-reboot 'Windows 10 (loader) (on /dev/sdh1)'

Then all I have to do is reboot the computer and it will go through the default countdown timer before booting to Windows 10.

:~$ sudo reboot

After you are done in Windows, simply reboot the computer and it will go back to Ubuntu as it is still the default.

Hope this helps as an alternative way to select your OS.

Terrance
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GRUB thinks that the OS choice prolog is actually being displayed and when no other OS line selection is made (via down arrow key), GRUB ultimately times out and starts loading the default OS on line 1.

However If, for instance, your desired OS is the 4th line of the GRUB choice list then right after the BIOS is finished and the screen goes blank (remember GRUB is now blindly timing you for a response) then immediately hit the keyboard down arrow 3 times just as you would if you could see the GRUB prolog display and then hit enter. GRUB will now load the selection in the 4th line.

The non-display issue has to do with the way GRUB's display configuration is set which in this case is not compatible with your display and you must make suitable changes to enable proper display of the GRUB prolog.

rdr
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