Computer Attempts to Turn On then Doesn't

My computer attempts to turn on, then like .3 seconds after I press the power button, it turns off. I opened the case to see what was the problem. The power supply does work, because it is showing lights before cutting itself off it seems.

So far I have a list of good parts, and they are as follows:
RAM
Graphics Card
Power Supply
CD/DVD Drive
Hard Drive
Heatsink/fan

I have bought a new motherboard and CPU recently.

They are: AMD FX-4100 Quad-core and ASRock 970 Extreme 3.

Any suggestions as to what is wrong?

Thanks!

A couple of things to start with:

You say "I have a list of good parts".

What makes you think they are good?

Do your fans start to move when you try to start?

Can you hear the hard drives try to spin when you try to start?

I have tested the "good parts" on my other computer to see if they spin and such and they are operational.

What about my last 2 questions?

Sorry, it slipped my mind :) lol

But, I can see the power supply fan and heatsink fan spin momentarily when I try to start it on my computer that won't run.

The hard drive makes no sort of sound or spin noise or anything at all.

Here is a series of troubleshooting steps from member TVeblen.

You should be able to adapt them to your situation.

Strip it down and then add components back, one at a time, to try and isolate the offending component.

The test (power off, power cord unplugged):
• Disconnect everything externally connected except the mouse and keyboard (printers, USB devices). If you are not using a wired mouse and keyboard see if you can borrow one.
• Disconnect the power and data cables from all the drives inside the computer (Hard drives, DVD/CD drives).
• Remove all the cards installed in the PCI slots including the video card. (be careful handling them and place them on a non conductive surface while testing).
• Remove all the RAM sticks (same rules as above).
Now connect the power cord and turn the PC on.
• The motherboard should start beeping. You should get a beep code that tells you there is no memory. This is good, it means the processor is functioning and the motherboard is good so far.
• Now add one stick of memory in Slot A1 and power on. More beeping: "no video card" beep code. This is good.
• Then add the video card and connect it to the monitor. You should get no beeping and you should see the BIOS screens, ending with the message that there is no boot device.
If you get no video then switch the one memory stick installed for another one and test.

Continue adding components one at a time.

If at any point the PC fails the the last component added was the problem one.

If you removed everything and there is only the Motherboard (with integrated video), processor, and power supply to contend with and it does not POST or show anything on the screen, then the problem is one of those three.

If you have tested by using another power supply then you are down to two. CPUs rarely fail, so motherboard is the most likely guess.

Try performing a CLRTC or Clear CMOS as a last ditch effort, and check the 3v battery. Both long shots, but what do you have to lose at this point.

I would say it's a 90% chance that your motherboard is the problem.

I had the exact same symptoms several months ago & replacing my mobo solved the problem.

I have the same CPU and MB, make sure that you have the CPU fan connected to the CPU fan Header 1 as there are 2 CPU fan headers, the other thing to chck is that you have the ATX power cable plugged in, I have just the 4 pin ATX plugged in and it works just fine that way.