Comment 0 for bug 1057532

After selecting an entry from the Grub menu and booting starts, the screen goes blank, and the monitor displays "no signal". When booting ends and X starts up, the screen comes back to life, and the LightDM login screen appears.
I'm using a Radeon HD 6850 with the opensource driver.

Kernel version: 3.5.0-15.23-generic 3.5.4

This is a regression, as the issue wasn't present with an earlier 3.5 kernel (.15). When I updated recently, I updated to kernel version .22, which exposed the issue. Updating to a newer version (.23) did nothing to fix the issue.

This bug may be related to the following bug: (although that bug appeared with Intel graphics hardware)
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1053269

ProblemType: Bug
DistroRelease: Ubuntu 12.10
Package: linux-image-3.5.0-15-generic 3.5.0-15.23
ProcVersionSignature: Ubuntu 3.5.0-15.23-generic 3.5.4
Uname: Linux 3.5.0-15-generic x86_64
ApportVersion: 2.5.2-0ubuntu4
Architecture: amd64
Date: Thu Sep 27 15:25:08 2012
InstallationMedia: Kubuntu 12.10 "Quantal Quetzal" - Beta amd64 (20120913)
ProcFB: 0 radeondrmfb
SourcePackage: linux