Jump the PSU, and plug in your fans and if your loop is intact, link it up to your pump as well. Mind to unplug the gfx card power, storage and optical power supplies. If it's running fans and pump then maybe you've got a mobo power problem? If these things work, connect it all back up as normal, make sure connections are solid (my 24 pin is a bitch to get in). Check your mobo's post lights, see if anything happens.