Welcome to the HP Support Community @zlive

One of the first components to be tested is the RAM -- the memory-sticks on your motherboard.
If that test fails, before the testing of the video is started, then you have a "pre-video" error.
If you have two sticks of RAM in your computer, remove one, and try to start the computer.
If necessary, remove the remaining stick, and re-insert the first-removed stick.
REO