Graphics Resolution- Upgrade /Blank Screen after reboot

[pathra]

// Updated As Of: 2015.1.10, Version 14.10

Are you having these problems?
- Error- "Cannot display this graphics mode"
- GRUB_GXFMODE-auto results in Blank screen problems on Startup? (this includes purple or black screen, flashing cursor, stuck at splash screen...)
- No Grub Menu?

Note: Keep checking back to this post and the next 2, as I edit them with the latest changes and workarounds.

The Table Of Contents (<-- Link) is on page 2. It has links to many graphics tutorials, workarounds and fixes in this thread.


Preface
Linux distributions such as Ubuntu, basically and simplistically run in layers like this--> You have a Linux kernel running. On top of that layer, you have a terminal session- running to interact with other layers. On top of that, you have an GUI, XTerminal session, X-Windows, XServer or also known as an XSession running to have a visually interactive session running. In each version of Ubuntu (and of distro's) an honest and earnest attempt is made to make each new version easier to use for a new user, in a way that is pleasing to the eye. Each of these changes does mean underlying changes in how things relate to each other layer... on a base that is trying to cover a myriad of hardware combinations, that users will install that distribution onto. Sometimes all of these combinations cannot be "foreseen." (For instance when a certain video card type is made by over a dozen different vendors...) These techniques are similar to the same problems in Unix and XServer (XServer Host & Client)...

Here is a short quick-reference of Linux short-cuts and hot-keys to help you get around and to help diagnose graphics problems in an Linux XSession. Some are also helpful later in just everyday kind of tasks. Like I said, this is only an abbreviated list, but I included them here because they do come in handy in diagnostics and the correction of boot and video errors:

<Ctrl><Alt><F1>
Switch to the first text terminal. Under Linux you can have several (6 in standard setup) terminals opened at the same time. Terminals start as tty0 and go up from there. Most of the time the normal boot text console, that is present "under" the GUI or XSession (in Ubuntu) is tty1, so you would press <Cntrl><Alt><F2> to get to it...

<Ctrl><Alt><Fn> (n=1..6)
Switch to the nth text terminal.

tty<Enter>
Print the name of the terminal in which you are typing this command.

<Ctrl><Alt><F7>
Switch to the first GUI terminal (if X-windows is running on this terminal).

<Ctrl><Alt><Fn> (n=7..12)
Switch to the nth GUI terminal (if a GUI terminal is running on screen n-1). On default, nothing is running on terminals
8 to 12, but you can run another server there.

<Tab>
(In a text terminal) Autocomplete the command if there is only one option, or else show all the available options.
THIS SHORTCUT IS VERY HANDY! This also works at LILO or GRUB prompt!

<ArrowUp>
Scroll and edit the previous command history. You can then use that command as is or edit it to change. Press <Enter> to execute.

<Arrow><Down>
As above, but go back to the next command in history.

<Shift><PgUp>
Scroll terminal output up. Work also at the login prompt in the tty text console, so you can scroll through your bootup messages to find errors and messages. Does not work to see terminal output that has been "cleared."

<Shift><PgDown>
As above, but scrolls terminal output down.

<Ctrl><Alt><+>
(in X-windows) Change to the next X-server resolution (if you set up the X-server to more than one resolution in /etc/X11/XF86Config). For multiple resolutions on my standard XVGA card/monitor, I have the following line in the file /etc/X11/xorg.conf (the first resolution starts on default, the largest determines the size of the "virtual screen"):
Modes "1440x900" "1024x768" "800x600" "640x480" "512x384" "480x300" "400x300" "1152x864" Whichever resolution you have as first in this line will be the default.

<Ctrl><Alt><->
(in XWindows) Change to the previous XServer resolution.

<Ctrl><Atl><Backspace>
Linux Ubuntu version 10.10 and previous- Kill the current X-session.

<Right-Alt><SysReq><k>
Linux Ubuntu version 11.04 and later- Kill the current X-session.

-- The "Linux shortcut keys" are just that, meaning Linux is already booted. to use them-- although "some" of them do work in the Grub CLI. *such as the <Tab> for autocomplete)

Basically, between the grub menu and the GUI Desktop Manager (GDM or LightDM), where you are getting a blank screen the only short-cut keys that "may" be available are the <ctrl><alt><F1 the F6> keys and <ctrl><alt><F7> key... which I mentioned, may not work even if you were not having graphical problems.. But if they do, you have some options.


General
Yes, with every new release of a distribution of Ubuntu, there seems to be similar and reoccurring problems that arise with "graphics" when trying the run a LiveCD and after the initial install and first boot. These are my notes that have help people through many releases of Ubuntu, up through Ubuntu desktop variants and server.

Basically, we want to make sure that the Grub menu boots. then verify that the kernel is booting, then that the XServer Session starts and displays.

Troubleshooting Flow Chart
This is to break this down into steps:
Step 1. Do you have a Grub Menu?
- Yes: Go to step 2...
- No: While booting, Press shift key (don't hold down) multiple times to see if the Grub menu will come up.
- - If yes on Menu, go to step 2
- - If no, use a LiveCD to chroot >> Change /etc/default/grub/ (line) GRUB_HIDDEN_TIMEOUT=00. and rerun "update-grub" Or you can do that chroot'ed from a LiveCD... instructions second half of post #3.
(Note- that will display a warning on boot- saying that timeout cannot be set to '0'... but it will display the menu, then and have no apparent challenges with that)
- - - If yes on Grub Menu go to Step 2
- - - If No, go to my fix on "Forcing Grub To Show Menu"... Link in Post #2
- - - - If yes on menu, go to Step 2
- - - - If No, reinstall grub and Start Step 1 from Beginning... Because it seems that Grub is not booting.

Step 2 "Does the Linux Kernel Boot?" At Grub Menu, go into edit mode and boot into a text console (see instructions below)
- Yes. Go to Step 3
- No. Messages will be verbose on what is loading, what are warnings and what are error messages. Shortcut keys will start to work as the kernel modules load. If if stops at an error, you will be able to use the shortcut navigation cuts to review the errors. Depending on the error, if it is a kernel error, you may be able to reinstall or renew the kernel image. If it is a device module, at least you have somewhere to go to reload that device module or driver.,,, Goal is to get a "booting kernel."

Step 3. From the Grub Menu, try to boot in Rescue mode/low graphics.
- If Yes, look for additional drivers and install recommended driver.
- If No, goto Step 4 to verify that linux kernel will boot.

Step 4. Can you boot a graphical XSesion from a text console session? From the command line type
Code:

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sudo service gdm start # substitute "lightdm" when appropriate


 

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linux    /boot/vmlinuz-3.16.0-28-generic root=UUID=32939def-1f4a-4134-9b56-bed2319a9216 ro  nosplash --verbose text