Just Posting what I’ve ran into w/ my HP Pavilion DV2911US.
I ended up w/ a blank screen and the cpu beeped a few times. The power would come on but could not access BIOS or start windows. I went through HP’s support re-seating the HD, RAM, hitting F10 etc. Finally sent it off, got it back and nothing. Sent it again, got it back, worked on it for an hour and the same thing happened. This time during HPs support the IT guy said to take out the top stick of RAM and try to get into BIOS. It Worked! We went through the different scenarious until it was narrowed down to “my top RAM slot” wasn’t working. So, if you get a black screen, can’t access your BIOS, etc… give this a shot. Now my Laptop is headed back again… planning on using Norton Ghost to create an image once it gets back.
Hope it Helps!