new build powering on and off

[Boneless]

I put together a comp and this is maybe my 10th build and maybe 30th upgrade all together, so I have some experience. When I powered up, the entire system would cycle on and off immediately after one another. All cables to HD and DVD drive are not connected. Can't even get into a BIOS. When I removed the 2 4-pin 12volt mobo connectors, it stays on. Also my cpu fan is plugged into the mobo, but never spins no matter if the 2 4-pins are connected or not. This is the power supply I'm working with

http://www.bfgtech.com/bfgr450wgspsu.aspx

and this is my mobo

http://www.gigabyte.us/Products/Moth...ProductID=3014

I'm not sure if it's a bad 4-pin connector and I should get a converter like this

http://www.newegg.com/Product/Produc...in%20converter

[EzyStvy]

Also my cpu fan is plugged into the mobo, but never spins

So the machine is overheating.....Can you spin the fan with your finger?

[glc]

Have you done this?

PROBLEMS with a NEW BUILD? Try This!!

[Boneless]

Ok, so I followed the guide and I get the same result. The phase LED's flash in unison on and off as it power cycles spontaneously. The cpu fan does a slight movement during the power on cycle, but never spins. The power supply fan cycles on and off like everything else. The phase LED's do stay on if I remove the 2 4-pin 12v mobo connectors, but the cpu fan still doesn't spin. I'm leaning to it being a ps problem since I figure it should boot even if the cpu fan doesn't spin at first. It would overheat, but that shouldn't stop it from booting into BIOS initially. What do you guys think?

[glc]

It's easy enough to do a quick out of the case test with a spare power supply. I dunno - I'd lean more toward the motherboard or a defective fan. Yes, a defective fan can cause a system shutdown.

[Boneless]

Originally Posted by glc It's easy enough to do a quick out of the case test with a spare power supply. I dunno - I'd lean more toward the motherboard or a defective fan. Yes, a defective fan can cause a system shutdown.

Does the fan have to be attached to the cpu to test? I have another fan attached to another system, but I'd hate to go through the hassle of removing it and replacing it after I'm done. Those 4 pins are a pain to remove with the mobo still in the case, and cleaning/applying thermal paste is another annoyance.

[glc]

No, it just has to be connected to the motherboard header.

[ChoboSeki]

Check the power supply first, but I believe it's the motherboard.

I came across 3 different clients using this motherboard and they were bad, one had the same problem.

They all worked great after I got a replacement.

If you have a warranty then RMA it for a new one.

[Boneless]

So, I RMA'd my mobo and got another(or they tested it and sent me back my own). It's still powering on and off within about a second of each other, except my CPU fan does go on now. I'm starting to think my case is shorting the mobo. Is there a certain type of riser that's needed? Because right now I'm using 2 copper(?) ones and 2(silver/steel-colored ones).

[glc]

Does it do the same thing with the motherboard OUT OF THE CASE as per the linked troubleshooting thread? If so, the case is not causing the problem.

[Boneless]

I think iI got the problem. It didn't work outside the box, so I started disconnecting the cables and trying it one at a time. Removing the 2 4-pin cables that connect to the mobo 8-pin slot was the problem. I need to try everthing in the case again, but do I need that. Mobo power supply connector?