Endless Rebooting on First Build

Hmm that is interesting you can't even get into BIOS. Try pressing delete or whatever key you press to get into BIOS anyways just in case it is rebooting right when splash is about to hit. Maybe you can get into BIOS and change boot drives around.

But if you absolutely cannot get into BIOS try unplugging your hard drive(s) and CD drives and try booting then. Let me know if it changes!

Also, make sure all your connectors are tight and secure!!! Check and double check them!

Also! Make sure your heatsink is installed properly. Even if you check and it is, check again! The computer could be rebooting because of over heating. If you have left it in the reboot loop long and it is over heating, you may have damaged your processor  
I hope that did not happen!

I did as you said and unplugged the HD and the CD drive, and there is no change. Sometimes it doesn't even last a second before turning off. The PSU is 550W so it can't be a lack of power...

Okay, check all of your connections. and Double check that heat sink!

And make sure all of your RAM and cards are seated into the Mobo. I bet you just have something loose or something.

Also. Make sure you RAM is 1.5V (look on the packaging or check online).

And please give me all of your specs (motherboard, ram, gpu, cpu, etc.)

I removed and reinserted the CPU, the heatsink, the RAM and the GPU, as well as the front panel connections and USB connections. Unplugged the CD and hard drives. I also tried using a different plug. The capacitors on the mobo do not seem to be broken or leaking. The RAM is 1.5v

Do I need to add extra thermal paste on my CPU? It seemed the Intel heatsink already had some so I didn't think I needed to add more.

I also tried to boot without the video card, and did not notice a difference in the reboot duration or frequency, if that helps.

Here are the specs:

MB MSI H61M-P21 (B3)
VGA SAPPHIRE|100315L HD6850
PSU ANTEC|TP-550 550W
CPU INTEL|CORE I3 2120 3.3G 3M
MEM 8G|GSKILL F3-10666CL9S-8GBXL Ripjaws
HD 1T|WD 7K 32M SATA2 WD1001FALS

You can add more thermal paste if you want. Some people say you should always put it no matter what. But my build now I don't think I did (was 5 years ago so can't quite remember).

You probably didn't have to take the cpu out, but that's okay. What I meant by connections are the cables that plug into your video card, etc. I should have been more specific, sorry.

Maybe I'm forgetting something. This is my first build after all. Is there a good guide I can go through to see if there is something obvious I'm missing?

http://www.newegg.com/Store/Computer.aspx?name=Computer...

http://www.youtube.com/watch?v=XFkykETgkoo - this guy is a dork and takes way too long but it's okay.

Read all of your manuals. Make sure all components have cables connected (like video card).

Also I should have asked. Do you get any beeps? 1 beep? multiple beeps?

http://www.maximumpc.com/article/features/step--step_gu...

http://www.tomshardware.com/forum/274745-31-step-step-g...

http://www.tomshardware.com/review_print.php?p1=1382

Nope, no beeps.

Ok well it may just be that you don't have a speaker. If you have friends or spare parts I would start swapping out parts that you know work. Very annoying, hope you get it fixed. I am going to be building my first build (all on my own) in a couple weeks.

you may have missed a stand off or your shorting the mb to the case. have you tried just the ram and video card with the mb sitting on your desk on top of the mb box??

If the mobo shorted it most likely wouldn't even power on right? He said it powers on but then reboots.

Bought a new PSU and hooked it up, didn't work. So I returned it and bought a new mobo of the same model instead, and still it didn't work. Goddamn.

Unplug all your case switch and LED wires, and use a flatblade screwdriver to short the power on pins (ref to your mb manual for the PWRSW pins) just to rule out a fault (it's unlikely but it happens), pref do this with as little connected as possible just to do a post test.

I solved the problem! I have no idea how, though.

Yay! now give me best answer because I obviously fixed it  

What I did was to restart it before it got a chance to reboot itself. Installed Win7 and all drivers, and now it refuses to connect to the uni internet because "Windows can't communicate with the device or resource (primary DNS server)." Both ethernet and a separate wireless adapter end up with the same problem.  

install your drivers man!

I did. I installed the LAN driver that came with the CD of the motherboard. It actually finds the connection and says "X Residence Connection" (the name of my connection), but then says No Internet Access. I can connect my XBox to the internet using the same ethernet cable just fine.

oh woops sorry I missed that in your post. my bad. contact your uni IT people maybe.

check under network settings that two buttons are one for auto dns and id. the router is going to be the dns server. you can tell if the setting are right by logging into most routers. if the pc not setting the dns up right you wont be able to do the 192.168.1.1 to get the router log on screen to pop up.