i have a old Hp desktop,( i have not used it in several years) i was trying to get it going for my brother to use. but it will not turn on. i mean nothing no lights or sounds whatsoever.any idea on what it could be? or what i could do to get it going? i did take the cover off and blow it out with compressed air. but is wasn't really that dusty Wanna kill these ads? We can help!