Boot problems on homebuilt system

Hi Guys,

I'm currently trying to build a new PC (first time).

I was having problems booting, so I've breadboarded the system and removed all the components except for the Heat Sink/Fan, and CPU. On turning on I received a steady series of beeps, so I installed a RAM module and graphics cards. Everything seemed to be running fine then, I was getting a single beep indicating a successful POST.

However, when I tried to connect my case fans, it seemed like something shorted out, and now I can't power on at all and the power and reset lights on the motherboard are continuously flashing.

Can anyone suggest what the problem might be?

Thanks