No, it's not a Grub bug. I initially wasn't using any grub_gfx_payload option, but the bug was the same, in Grub 1.99 as well as in Grub 2.00. Then I added it, and while the resolution of the Grub menu changed properly, it nothing about the black screen bug.
It's a kernel regression. I've now installed and booted into the new kernel 3.5.0-16.25 that was offered today. Also here though, no change, still a black screen during boot - all the same. I've updated the desription above, listing all kernels with which I had the black screen bug appearing. ** Description changed: 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. - Update: Installing the new kernel 3.5.0-16.24 did not fix the issue - either. + Update: Installing the kernels did not fix the issue either: + 3.5.0-16.24, 3.5.0-16.25 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 3.5.0-15.22 / 3.5.0-15.23 / 3.5.0-16.24 + Package: linux-image-3.5.0-15-generic 3.5.0-15.22 / 3.5.0-15.23 / 3.5.0-16.24 / 3.5.0-16.25 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 -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1057532 Title: Monitor goes black ("no signal") after Grub, comes back to life when X starts To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1057532/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs