Ok, here is what I have in front of me. First, I am a geek. I've been working on PCs since the first sound blasters and 8088's. I'm not a trained tech or anything, just a hobbyist. I don't know everything, but I know enough to be dangerous. I decided to go to water cooling after a life of air cooling. Ripped my working machine apart to put in the top mounted radiator and pump, etc. While I was at it, I opened up some of the grills for better airflow, etc. Finally received all my WC parts assembled my loop (CPU, VID, temp probe, rad, pump & res). Reinstalled & jumpered the power supply to let the system run. No leaks after about 18 hours or so. So I started to reinstall MB & everything. Used Ceramique (I've been using for a while and like it). reinstalled everything that was working before the mods (same ram, vid, cpu, nic, sound, etc.) Finally got the last thing together and pushed the power switch and nothing happened. Hit the switch on the PWR supply to see if I bumped it in off position. Nothing. Reattached all cables to MB to see if I didn't have something down all the way. Nothing. Pulled apart the switch on the front of case & tested with a multimeter. It works. Looked everything over again. Nothing seems out of place. Unpluged the ATX and jumpered it to see if PWR supply was acting up. As soon as I did, pump, fans, fan contoller, everything lit up and ran. So I plugged it back in to the MB and hit power again. Nothing. Pulled my NIC, Sound, and Raid card and hit the switch. Nothing. What is going on here? I'm at a loss. Did my previously working MB bite the big one? Did I miss something. Also, the PWR supply is a Seasonic 550w modular so it should be able to juice the little extra added by the pump. Everything worked fine before even in heavy gaming or photoshop. Please help. I think I'm loosing it on this one. Thanks to any and all who try to restore my sanity.