Sinko :
Need more information. Can't help you solve anything if we don't know the specifications, model numbers, etc.
mobo: Asus x99 deluxe II
psu: Corsair AX860i (note: whenever I start PC psu reboots once or twice until it turns on)
gpu: MSI gtx 1080
cpu: i7 6850k
cooler: Corsair h110i v2
SSD: Samsung 850 pro (512gb)
Case: Corsair 760t
(Note: mobo leds, case leds, and ssd is working. CPU cooler does not pump the water, fans dont spin and gpu fans dont spin. But, one time I booted it up everything worked fine. So it probably is not a connection issue.)