Ubuntu 14.04 Suddenly Fails to Boot

My Ubuntu installation has decided not to work anymore. I suspect it's something graphical or to do with memory. Read on for more.

Background.

I installed Ununtu 14.04 on my laptop a few months ago and have had no problems whatsoever with it up until a few days ago. I had closed the laptop temporarily and it went into Sleep Mode. Then when I opened it again, it awakened. Cool. However, the screen remained completely blank except for when I moved the mouse or pressed a key on the keyboard, which briefly flashed my desktop wallpaper. After rollong my eyes and cursing the previous fifty years of software development, I performed a hard reset, got to GRUB2 and proceeded with loading Ubuntu. Now the boot process stalls shortly after the GRUB screen and I am left with a blank screen and a blinking cursor.

Attempts at Recovery.

1. Loaded "Ubuntu with Linux [latest version available on laptop] (Recovery Mode)" and performed all available tasks. Interesting note: I cannot use the "failsafeX" option; selecting this option fails to load Ubuntu with limited graphics. It attempts do so, but fails and reverts back to the Recovery screen.




2. Tried to reinstall Ubuntu with the same USB drive I used to install it in the first place. I can get to the first menu, but when I select "Install Ubuntu", it quickly crashes with the last line ending "VFS: failed to mount root fs in unknown block [2, 0]". This happens every time.




3. In Boot Command list, removed "quiet splash" and replaced in with "nomodeset" because several people in different treads suggested this, without giving an explanation as to why it should be done. So naturally, I gave it a go. It didn't make any difference as far as I could tell.

Summary.

1. Laptop: Lenovo T410, had Windows 7 previously installed (still exists on a separate partition), Intel CORE vPRO i5, 4ĢB RAM, Intel Graphics.




2. Laptop was running fine, sent it to sleep, woke it up, couldn't log in/do anything. Rebooted it.




3. Booted to GRUB screen, selected Ubuntu.




4. Ubuntu fails to load. I get a flash of "Loading initial ramdisk" before I get the blank screen with the blinking cursor.




5. Tried a few things. None worked.




6. Stumped. Came online for help.

If anyone can shed any light over what's going on here, I would be very grateful.

EDIT:

Responses.

dadexix86.
1. I have never manually performed a filesystem check.

2. Ubuntu does not boot with an older version of Linux. I get the same result, every time.




3. I did not suspend it after an update. I was not running any "exotic" processes. By exotic I mean system-critical, or otherwise important to the running of the system-, processes.




4. I have no external repositories or software.




5. Thanks for getting back me.

anonymous2.
1. I can still boot to Windows.

2. I have not performed a memtest. I will do so now and report back. | Memroy check completed, no errors.




3. Thanks for getting back to me.

Android Dev.
1. No problem, homie.

ComputerGuy.
1. I don't have Nvidia graphics.

2. I will try your suggestion and report back. | OK, I tried resetting Unity and it returned "WARNING: no DISPLAY variable set, setting it to: 0" and "ERROR: the reset option is now deprecated." So I don't know if that worked. I tried reinstalling LightDM, but I need network connectivity to do that, and I'm not able to enable this. I'm currently looking into that.

Thanks for the help so far, folks.