on power button press any fans spinning or something or just lights on the fans?
i'd start with removing all connections to smart device and corsair's fan controller and connecting fans directly to mb.
for back fan you have sys_fan1 bottom left of the processor, for top fan you can use pump_fan1 header and front fans attach to sys_fan3&4 (p26 mb manual).
also make sure you dont have any bolts or other metal parts stuck between mb and tray of the case (if you have torchlight you can use it to have sight on bottom part of the mb