HP ZD7000aptop

Does someone know how to reach a CMOS battery on HP ZD7000 laptop or is there any jumpers to reset the BIOS? Somehow the screen stoped showing anything. I can hear the Windows start up sound but the screen is black at all time. Looks like windows is sending video signal to other display. I tried everything I know with no luck and a last thing remains is BIOS reset. Thank you.