I have an HP 15 f125wm laptop that doesn't have a VGA port. It has an HDMI port so I just bought an HDMI to VGA cable. But when I connect the cable nothing happens. The monitor doesn't pick up any signal at all. All I could find from HP was a manual on how to connect the cable to the ports but that doesn't help. Has anyone else had this problem or know how to troubleshoot it?