I don't have any experience with that particular motherboard, but in general:
No beep usually means a PSU or Motherboard problem. Could also be a failure with a required component like the CPU fan. Or a short circuit. Could also mean the ATX12v (8-pin connector) worked its way loose.
I'd pull everything out of the case, put the motherboard down on a layer of cardboard, and try to get it to power on with just the CPU and a single DIMM installed. Then reconnect one thing at a time. If your motherboard is shorting against the inside of your case (this is likely if it works outside the case but not when installed), a couple layers of parchment paper under the motherboard before you screw it in may be adequate.
If even THAT doesn't work, it'd be time to start swapping components until you find one that works. But that usually requires you have some spare components to swap with...