|mmm... doesn't sound good; may well be the MoBo hath died a death of some sort or other...|
Are "all" voltages as they ought to be on the system - at suitable test points/positions?
You say system is only 6 months old? I'd be seriously inclined to contact vendor (invoke the system warranty) if you bought it as a complete working system...? If you built it then invoke the warranty for the MoBo and/or the PSU?