MSI X58 Pro-E , Pc reboots after 3 seconds no screen.

[maxxie]

This are the components of my PC:

Case: Cooler Master Stacker 832 SE incl. Zalman ZM-MFC1 Plus fancontroller and 4 fans
Processor: i7 920 Socket 1366 quad-core proc. van 2,66GHz 8MB cache
Motherboard: MSI X58 Pro-E
Memory: Corsair XMS3 CMX4GX3M2B1600C9 4GB
Graphic card: VTX3D HD ATI HD5670(HDMI, VGA, DVI)
Power Supply: Cooler Master M620 modulair
Harddisk : Samsung HD103UJ 1TB 7200rpm 32mb
Software: Windows 7 Ultimate 64 bits

I buyed this PC second hand. I have seen it working.
But when i came home it didn't, when i start the PC the PC stays on for 30 seconds everything seems to work, but i see no images on my screen and then my PC stops working and then reboot, and that happens over and over.
So i tried to reset the bios manually but that didn't seemed to work. I tried everything i know about computers. I changed the BIOS Battery, tried the CMOS button and a motherboard speaker. After a lott of testing i know it have to be 1 of this 3 parts: motherboard, processor or the ddr3 memory. I think it is the motherboard just because it makes the most sense. And now my PC restarts after 3 seconds

But In the time i tried to fix my PC, the PC gave a screen like 7 times.
The First showing a screen that said overclocking has failed.
6 others were that i could start my PC (f2) or go to BIOS (f1), i went to the bios and me screen froze or my keyboard stopped working so i could do nothing and had to restart the PC and see the same problem. This happend 3 times.
The other 3: I came to the screen and i pressed f2 and windows started like nothing happend and i could do everything i even restarted the PC and it worked also, but after that i turned off the PC for 2 hours, same problem came up.
                  I pressed f1 and went back to failed default settings, then the PC worked for 4 days and i could do everything with it. But after restarting my PC after four days same problem again.
                  I pressed f1 checked my temps and they were just fine and tried to start op windows normally but i had disconnect harddisc to conclude it out, so i couldn't restart the PC and then it never worked again.

The computer only works 1/100 times randomly or someting like that i have put a Lott of time in it and i only saw a screen 6 times. Newest BIOS on it.
It seems to be the motherboar, but i could be wrong maybe someone else ever had this problem that can help me.

 

[Henry]

Remove all of the parts from the MB including cables from PSU. Re- seat everything and ensure that all of the parts are fully seated in their slots and in the case of RAM, VGA and the PSU cables they are all locked firmly in place.

 

[maxxie]

Remove all of the parts from the MB including cables from PSU. Re- seat everything and ensure that all of the parts are fully seated in their slots and in the case of RAM, VGA and the PSU cables they are all locked firmly in place.

I already did this, multiple times.
Everything is locked firmly
But that doesnt matter, because it isnt working

 

[Bernhard]

If it is an intermittent problem, then I would double/no triple check all connections. Alternatively I would also try with another known good PSU to ensure that its not possibly the PSU that is on its way out.
Also try by removing all RAM modules and only trying with one to see if it will boot.
Clear CMOS with power cord removed. >>Clear CMOS Guide<<

 

[maxxie]

If it is an intermittent problem, then I would double/no triple check all connections. Alternatively I would also try with another known good PSU to ensure that its not possibly the PSU that is on its way out.
Also try by removing all RAM modules and only trying with one to see if it will boot.
Clear CMOS with power cord removed. >>Clear CMOS Guide<<

I more then triple checked all the connections.
And i almost know for sure that the psu isn't the problem, because i tested it on a other PC and it worked fine there and when the PC is on it stays on until i restart the PC, so the psu is working fine.
I cleared the CMOS already multiple times, yesterday when i cleared it my PC started working again, but when i restarted the PC it and my PC stopt functioning, i tried it again and then it didn't worked and i tried it other times also, and it also didn't worked then.

So the problem is the PC wont start 1/50 times, when it's on it works fine and you can restart it and it still works, but when you power down the PC for a couple off houres and then boot the PC it doesn't work again.