About a month ago I managed to put 5volts thro the com1 port which stopped it dead. After half an hour it started up ok but built-in sound shot, but a sound card cured this. Now it starts when it feels like it, sometimes straight away other times it takes 10-15 mins of pressing power button before it goes. The green motherboard light comes on every time, but when it wont start if you hold the power button in the green light goes out, then press it again & all the fans go for 5 seconds or so. Have reinstalled windows, cleared cmos, no better. Think I may have half killed motherboard, any other ideas anyone? When it start it runs perfectly.