Black screen on boot

[LNXlady]

Ah ok then don't try it.
Hmm... the problem is I don't know if the issue is in the kernel, drm or the xorg-driver of Radeon.
Of course you could try installing a mainline kernel from ubuntus extra ppa for mainline kernels. However if it's an issue in the xorg-driver or drm it won't be able to fix it.

Could you give me instructions for that? After your vacation is fine, though.