New build not powering.

[shadowfire452]

I ordered a new build, and I'm sure all the parts are compatible, but it doesn't power on. When I switch the psu on the CPU fan does about a half a turn and then nothing. About 50% of the time it happens as soon as I switch the psu on, and sometimes it waits until I press the power button. I'm using a gigabyte GA-78LMT-S2 motherboard. I have 2 hunches so far, on the mobo the front bus pin out is all together, but the wires for the h.d.d. Led, p+ and p- are too short to reach it, so I just have the power and reset buttons hooked up. Is this a problem? Secondly, the CPU fan came with some thermal paste already on it, so I didn't bother putting more on, however when I attached it, it swiveled around on the processor and didn't seem too attached until I secured it. Could that be a problem? Anything else?

 

[Onus]

Did you mount the motherboard on standoffs or raised bumps (but not both), and use a standoff only where there is a mounting hole?

 

[shadowfire452]

Did you mount the motherboard on standoffs or raised bumps (but not both), and use a standoff only where there is a mounting hole?

Raised bumps only.

 

[Onus]

Is there any possibility that you used a PCIe power cable for the CPU, or the CPU power cable for your graphics card? Either of those would cause a short circuit that would make the PSU instantly shut off like that.
If not, disconnect power to all drives and all fans (except the CPU fan), and see if the system will power on. If so, one of them may have a short.

 

[shadowfire452]

Is there any possibility that you used a PCIe power cable for the CPU, or the CPU power cable for your graphics card? Either of those would cause a short circuit that would make the PSU instantly shut off like that.
If not, disconnect power to all drives and all fans (except the CPU fan), and see if the system will power on. If so, one of them may have a short.

Cables are in correctly and I've tried unplugging everything but the CPU fan to no avail. I have built 4 other computers before but I've never had this issue. I'm hoping it's not a faulty mobo - all the parts are brand new - but I'm not sure how to check.

 

[Onus]

Remove the cooler, remove the CPU and check for bent pins or thermal paste causing a short. Bent pins can be straightened by using the tip of a 0.5mm mechanical pencil.

 

[shadowfire452]

Thanks for the tip with the pencil, however it turns out that the case did not have raised bumps as I thought it did, I installed the standalones and it worked. Thanks for all your help!

 

[Onus]

I'm glad nothing got fried.