How can I fix the resolution of my live USB?

Question

I'm trying to install Ubuntu from a USB stick. I can boot into the stick and doing so brings me to a black screen with white text which says grub at the top and has four options to choose from: Try Ubuntu Without Installing, Install Ubuntu, OEM Install and Check disc for Defects. At the bottom it instructs me on how to navigate. Pressing c brings me to a command line looking screen which says grub where the name of the machine would normally go and escape returns to the first screen.

Checking the disc goes to a purple screen witty orange loading dots and works fine but the first two options both cause the screen to go black for a second, then the normal purple loading screen appears and finally TV turns to its default background colour and a box saying "Not Supported" appears, almost certainly referring to resolution.

How can I change the screen resolution without actually being able to see what I'm doing, or by using grub, or by opening files on the USB stick using a Windows computer?

Edit: This is on a John Lewis TV Screen, connected using VGA. Also I am able to bring up the normal terminal by pressing Ctrl-Alt-F1. Closing the terminal with Ctrl-Alt-F7 brings up a blown up portion of the normal Ubuntu Desktop for a second before the invalid resolution message returns. Trying to change the resolution with 'xrandr --output VGA-1 --mode 1024x768' returns the message "Configure crtc 0 failed" and 'xrandr --output VGA-1 --auto' did nothing.

Are you really using a coaxial TV screen, or are you talking about a VGA CRT? — anonymous2, Jun 08 '16 at 12:56
I'm using a John Lewis TV, plugged into the VGA port. Windows works fine. — ToastedFishSandwich, Jun 08 '16 at 13:24
Do you have another VGA monitor you could plug in temporarily to make sure the graphics card is sending a signal out? — anonymous2, Jun 08 '16 at 13:28
Awesome, the desktop shows up fine on the second screen. Maybe it's time I got myself a proper computer monitor? — ToastedFishSandwich, Jun 08 '16 at 13:43
It could be. There's a suggested answer you can try. You could also try looking into drivers for that screen on Ubuntu. I'm afraid I always use generic screens, so I don't know much about that. — anonymous2, Jun 08 '16 at 13:45
Have you tried nomodset at explained in https://askubuntu.com/questions/162075/my-computer-boots-to-a-black-screen-what-options-do-i-have-to-fix-it/ ? — user.dz, Jun 16 '16 at 20:41

score 0 · Answer 1 · answered Jun 08 '16 at 13:41

0

you can vi /etc/default/grub and change the line GRUB_GFXMODE=(resolution) and change it there to make it boot up to the specified resolution.

answered Jun 08 '16 at 13:41

madechai

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Bear in mind he had no screen. – anonymous2 Jun 08 '16 at 13:53
Well, if he cant connect to a monitor that works, there isn't much that he can do. A live usb and monitor should do the trick. – madechai Jun 09 '16 at 19:23

How can I fix the resolution of my live USB?

1 Answers1