Motherboard or CPU?

[Lutranereis]

I built a new computer yesterday, my fourth in total. I got it all together, turned it on and got to the BIOS page on the first time. Then I turned it off, went to make a bootable USB for Windows on another rig, and when I tried to turn on my new PC again, it wouldn't POST.

Instead, it went through an infinite cycle of turning on for a couple seconds, off, then on again. The fans and LEDs all come on. At first, I though it could be a PSU issue, so I tried another PSU and the same thing happened. I reseated my graphics card, even tired to turn it on without it. I even tried to put in new RAM. Finally, I took everything out of the case and put it together on some books to make sure there was no shorting on the chassis. Nothing has worked so far.

So now I have it boiled down to either my Motherboard or CPU. Should I just send both back for a replacement, or should I just try to send my motherboard back and see if that does it? Are there any other steps I haven't thought of to check?

I really appreciate some help with this. I'm at a complete loss of what to do next.

I have a Gigabyte GA-Z87N-WIFI and an i5 4570.

 

[rolli59]

Well do you have a case speaker?
Any way here is our trouble shooting guide http://www.tomshardware.com/forum/261145-31-perform-steps-posting-post-boot-video-problems
If it comes down to board or CPU usually it is the board.

 

[Lutranereis]

Well do you have a case speaker?
Any way here is our trouble shooting guide http://www.tomshardware.com/forum/261145-31-perform-steps-posting-post-boot-video-problems
If it comes down to board or CPU usually it is the board.

Thanks for answering, and though I have a case speaker in my drawer of miscellaneous computer crap, I have no speaker header on my motherboard. That kind of irks me, seems like an important diagnostics tool for any system builder. Perhaps there's another way to get beeps from a motherboard without a speaker header that I'm unaware of?

As for that guide, it's a very, very useful guide. I've followed the steps in it last night, and no luck at all.

Glad to hear I probably won't have to send back both. This is the first time I've run into a problem like this. Can a motherboard POST once and then never again just like that?

 

[rolli59]

Yes that can happen! Power on something fails.

 

[Lutranereis]

Yes that can happen! Power on something fails.

Alright, thanks for the insights. I'll send the motherboard back and get a new one. Hopefully it will clear the whole thing up.