Hi there,
in the user manual it states:
it is recommended that a power supply that can withstand high
power consumption be used (500W or greater). If a power supply is used that does not provide the
required power, the result can lead to an unstable or unbootable system.
I'm not saying that this is the problem but it is something to bear in mind.
What Graphics card are you using? - You need to install a GPU with this motherboard/CPU combination as the Athlon 860K chip doesn't have graphics capability.