I gotta Hp Compaq dc5750 for a friend , added Ram, a slave drive , and a new video card . Worked great , I sent it to him, he got it.On boot it has 9 beeps and nothing but a red flashing light. I have read that 9 beeps can be everything from a bad battery to a bad mobo. I read on here that it is "9 short ROM checksum error- The contents of the system BIOS ROM does not match the expected checksum value. The BIOS ROM is probably defective and should be replaced' So what does this mean? I had my friend remove 2 sticks of ram and it still beeped then I had them remove the other 2 and put the first 2 back in and it still beeped.