Ubuntu does not boot without "nomodeset" in grub

[gore-amit]

I was having a working 12.04 64bit system. However suddenly after couple of abnormal shut down of system. I am not able to boot normally.
Machine boots but there is default purple/black screen. No textbox or login buttons.
After editing the grub and making "nomodeset", machine boots.
However I can see an "AMD Testing use only. Unsupported Hardware" watermark at right bottom corner of screen.
I have not activated "ATI/AMD proprietary FGLRX graphics drivers"

Following some forums, I tried to edit grub and make it nomodeset and then tried update-grub but it fails.
I keep getting "/usr/sbin/grub-mkconfig: 36: /etc/default/grub: Syntax error: EOF in backquote substitution" error message.

Also tried to use Boot Repair but still not able to fix it.
http://paste.ubuntu.com/6594930/

Attaching the grub file for reference (grub.txt).

[gore-amit]

While booting i can see following entry:
linux /vmlinuz ........ ro drm.\ debug=0xe plymouth:debug

[oldfred]

Silly computers do not like typos. And often those are the hardest to find.

quite splash nomodeset

quiet splash nomodeset

[gore-amit]

Thanks for pointing out.
I was not able to fix it any which way so I just reinstalled it and it worked.

[steeldriver]

FYI your GRUB_CMDLINE_LINUX_DEFAULT line also had a Unicode double quote instead of a regular ASCII character


GRUB_CMDLINE_LINUX_DEFAULT=”quite splash nomodeset"