hi got the similar setup with an A8-3850 and a MSI A-55 motherboard with a good 400w PSU from circle:raw power series(you guys mustn't have heard about it)with 77% capacity output,System works around 2 hours,suddenly stops,no more booting tried reinstalling,system stops running while installing after around 30 minutes,at last system doesn't even start up.I fear it could be the power supply?kindly suggest.The PSU seems to be efficient enough:could it be some of the peripherals defect?the sooner the reply,it would help my friend.