New Computer Won't Turn On

I just built a computer for my friend, and it won't turn on. When I hit the power button, the fans that are connected directly to the power supply turn on for a few seconds, than off for a few seconds, than back on for a few seconds and keeps repeating. nothing plugged into the mobo turns on. I have a new antec TruePower Trio 650Watt so i am pretty sure thats not the problem. It is a Gigabyte GA-965P-DS3 motherboard with a Core 2 Duo Extreme Proc. I also have a nvidia 8800GTS videocard, and 2 gigs of corsair memory.

Does anyone know why it isnt turning on correctly? any ideas would be greatly appreciated. thanks.

that's normal for the DS3 mobo when you first use it, it`ll continue to turn on and off its all in the manual . It should stop doing it the next time you boot.

I worried when it first happened too but it all works fine after awhile, I would also recommend turning off the fan controls because if you watch, it`ll stop and start and that just worried me too much so now it goes full speed.

how many times should it turn on and off? the manual just mentioned that it would do it once the first time to reset the cmos or something like that. After it kept turning on and off every few seconds for a couple minutes I would turn off the computer.

not sure, When it first did it with mine i turned my comp off but I hadnt finished building it either. Once it was all done i turned it on went into the BIOS etc made sure everything was fine and it hasnt done it since.