I recently installed Ubuntu 12.04 alongside Win7 on my HP Pavillion dv6-2020eg. Soon, a first problem occured: suspension mode isn't working as expected. Suspending the laptop is easy (closing lid or selecting in menu). If I then try to wake up the sleepy bugger (opening lid or pressing random key) all the lights turn on as usual, fan is working etc, but the screen stays turned off.
According to many forum threads, quite a number of people seem to have a similar problem, although none of their solutions or work-arounds worked for me. The keyboard seems to be turned off, since I neither can activate num-key and capslock nor do the wifi and mute buttons work. The on/off button is working fine plus I'm able to eject the CD-drive.
After the following forced reboot, again, monitor stays turned off. I have to disconnect it from power and battery to get it working again. Strange.
ATI Mobility Radeon HD 4xxx CPU: AMD Turion(tm) II Dual-Core Mobile M500 × 2 Kernel Linux 3.5.0-32-generic Gnome 3.4.2