New build won't boot

I just got done putting together my computer and every time I try to boot it up for the first time, the led lights on the fan and lights on my motherboard flash for just half a second and then fail to boot. I can only repeat this when I turn off and back on the PSU.

(I am fairly new to all this stuff so correct me and ask me questions if I forget something or say something dumb)

My specs: 

MOTHERBOARD - msi z77a g45

CPU - intel i7 3770k @ 3.5GHz

GPU - Asus Geforce GTX 770-DC2OC-2GD5 2GB 256-bit

RAM - 8 GB (2x4GB) G.Skill ARES 240-Pin DDR3 SDRAM DDR3 1600

PSU - Rosewill HIVE Series HIVE-750 750W Continuous @40C, 80 PLUS BRONZE Certified, Modular Design, Single + 12V Rail, ATX 12V v2.31/EPS12V v2.92, SLI Ready, CrossFire Ready, Active-PFC Power Supply

CASE - Zalman z11 HF1

HDD - Western Digital 1TB HDD


Hi i feel your pain, my last build wouldn't boot so let's go down the list

 1)are both the 24pin and 8pin connectors fully connected?   2)Is the ram seated properly?   If everything is connected do the paper clip test on your PSU    If everything checks out then you may have a bad MOBO.  (which is what was the case for my build) well good luck.

Are there spacers underneath your motherboard?

If you didn't put these on it will either cycle like this or short your mobo.

Yes, i ended up researching the issues myself and rechecked the 8-pin, the 24-pin, and the ram. all of that is plugged in correctly and positioned in the right places. 

I did read on a forum somewhere to try unplugging the fans from the case. I unplugged the fans from my case that were hooked directly to the PSU and it turned on just fine. I have two other fans in my case that are connected directly to the motherboard that are working just fine. 

I tested this multiple times and got the same results. I tried unplugging the HDD power connectors and it turned on. I then tried again with just the HDD connected, it turned on just fine. Connected the case fans to the PSU, same issue that happened before. Unplugged case fans, works fine.

So, i found the source of the problem, but I'm stuck on how to fix it. Is my 750W PSU not enough power? are my fans connected improperly? 

750W is more than enough power for your build. I used to have my fans connected directly to my PSU, but this is loud and dusty but did work just fine. After a while I re-wired the fans to the MOBO, and this also works (better). MY PSU: 520W

My opinion: you have a bad PSU

so i did a little looking around on some forums and i think i realize my mistake now. The cable i had plugged in to my case fans were all 4-pin molex. Another cable that was attached to this cord was a floppy drive power cable which looks very similar to the 3-pin fan connectors that i have installed (except the power cable is 4-pin). I plugged the 4-pin floppy drive cable into the 4-pin sys fan connector. 

I have no way to try this at the moment, but after just a little research i feel like this is my critical mistake. When i do get home later today, i'll update you guys on whether that was the issue or not.

I found this website here which shows the power connectors to each device. scroll down til you see the 4-pin peripheral power cable (these are the same as my fan connectors) and one below that is the floppy drive power cable which i think is the same cable that i mistook for a fan connector and plugged into the sys fan on my motherboard


So, as it turns out, I was correct. All fans are currently running with the computer running very well with no hiccups. All i had to do was unplug that floppy drive power cable connected to my motherboard haha. I made a n00b error and so far, everything is just dandy. 

Thank you to all who responded to my posts and gave suggestions, you guys helped me think through what I have done wrong in setting up my computer. Time to go play some games :D