computer wont start

[scarab15]

Hope somebody can help, real problems with my computer.wont turn on most of time and when it does, IT DON'T LAST FOR LONG.

Everything I have tried so far.
Pressed power button for 60 seconds without power cord in.
PSU is OK (Done Test)also tried a new PSU,Still have same problem.
tried a loop feed just in case power switch on case faulty,would not fire up.
Motherboard has been changed, Still no power.
removed motherboard from Case, put all parts back on Hurray it fired up Re-installed everything on Hard drive (1tb Sata drive)Switched off,next day NOTHING.put everthing back in case,NOTHING
Took motherboard out of case re-fit the old motherboard,installed CPU (Intel 2500k)put both Memory modules in (vengence 4gb x2)Used old PSU, It fired up,switched off it fired up again did this 2 more times.I installed BACK IN CASE WITH Harddrive and Graphics Card (Palit ge-force 560ti)It fired up,I then started putting other cables for usb sound etc,It WOULD NOT TURN ON.I back tracked back and removed everything to the point were it fired up But NOTHING no power again.
I have put my new motherboard back in the case re-fit everything and i am stumped.HELP

 

[ParalizedTime]

Have you tried putting one stick of ram in at a time?

 

[scarab15]

tried that, no different

 

[scarab15]

I have just uninsulated all components, I have started by putting processor back in with 1 stick of memory IT FIRED UP- put second memory stick in IT FIRED UP I have put graphics card,harddrive in,IT IS REBOOTING ALL TIME.
I removed harddrive STILL REBOOTING ALL TIME,Re-attached harddrive,Removed Graphics card STILL REBOOTING ALL TIME,Re-attached.So at the moment I am sat here with a computer which is trying to boot up but cant???

 

[jmacavali]

Now it sounds like it's a Windows software issue. How far does it get before it reboots?

 

[scarab15]

Uninstalled a memory module,IT HAS STARTED WORKING.
Hope this is not a short term thing as I have update everything and at the moment I can switch computer off and it will switch back on.
I now need to close case and put back to were it belongs as it is in middle of floor at moment.
Fingers Crossed.