I have a HP Pavillion 6 desktop Computer( Windows 7) and it will not start up. A couple of days ago my husband was on the computer and it just went off. So I pressed the button yellow light came on (normally a blue one), unless it wakes up from standby) fans started briefly and then went straight off again. The LED light on the back is on and doesn't flash. I have followed HP instructions. Cleaned it inside. Checked connections. I did notice a couple of cables connected one end only, but they didn't seem to be able to connect to anywhere else as they weren't long enough. Any suggestions. Please note I am not computer whizz!