it should be the hard drive , i had two ps3 the came in that would turn on fine except with no image or audio, the first one when i plugged the hdmi in it was extremly loose so i ruled it as the hdmi , it made sense that it would be the hdmi so i left it like that , the second one i had already worked on , it was having issues trying to format the hard drive and when it did it took a whole day, when the customer brought it back it was turnign no but with no image. so i thought to my self....hmmmm the hard drive was having problems before maybe if i test another one on there it could fix or make it better so i did and as soon as i installed a used one the video came on and i did had to format that hard drive and install an update but that got video and audio back on , thats not it , i got the first ps3 that i thought was the hdmi and i installed another used hard drive and got image on that ps3 again so wala