This is usual problem in Hps machines when they start gettin old. Four beeps thats the motherboard problem, to narrow it down its the vga or rather graphic card. If you have proper tools you can do this on your own . otherwise take it to a good IT tech they will open the laptop resolder it properly and it will be fixed. I had similar problem and i fixed it with my friend in same way.its working fine. Bonfantry M