new pc shuts down shortly after starting BIOS

[Jojojamo]

To start out, this is my first time building a PC.

So after spending all morning figuring out that the reason the computer couldn't start (aside from a little power hiccup at first) was because the mobo wasn't properly grounded, I've finally got the power to start.

Now, it runs for a solid few minutes. But, while I'm browsing the BIOS options, it just shuts down every time. No blue screen or anything on the screen, it's as if the power switch was just flipped off. Taking out one memory stick and leaving the other in B1 (2gb - this one) helped by making the BIOS actually come up and stay put a little longer, but I still can't keep the system running. Any ideas?

Here's my setup:

video: GeForce 9800 GTX 512MB
mobo: ASUS Maximus II Formula LGA 775
cpu: Intel Core 2 Duo E8400
psu: COOLER MASTER Real Power Pro RS-650-ACAA-A1 650W
hdd: Western Digital Caviar Black WD5001AALS 500GB 7200 RPM 32MB Cache SATA 3.0Gb/s
dvd: LG dvd rw
ram: (2x, but using only one of them now) Crucial Ballistix 2GB 240-Pin DDR2 SDRAM DDR2 800 (PC2 6400)

Could my processor be overheating (is this possible after only a couple of minutes in BIOS)? Do I need to use thermal paste for the cpu heat sink? Could it be a short? Or does a short occur right away, rather than after a few minutes of power? Power supply?

I think that covers it. If anybody can help me out I would really appreciate it.

 

[Jojojamo]

Ok, I think I've found the problem:

The fasteners on the included intel cpu heatsink are horrible. They just don't want to all be clipped in at once and I'm worried I'm going to push too hard and damage the mobo. As a result, it keeps coming loose and causing the cpu to overheat. Anyone know what the trick is with these things, or should I not worry so much about pushing harder on the clip buttons?

 

[oldskool]

Can you post a picture ? Is it the type that hooks on one side and clips on the other ? A little catch to hold it in place ? Does it look like this ?


SOURCE: How to Build Your Own PC - Securing the Heatsink Clip

Pry out to release (removing) and it is pretty much the opposite installing, sometimes it can be tricky. Be patient, you don't want to gouge your motherboard.