CPU,motherboard Bootup Problem

Please refer to this link for all the details first:http://www.tomshardware.com/forum/forum2.php?config=tom...
So my mobo started giving me problems I gave it for repair, it comes back from the company, 2 weeks hence when I hit the power button comp turns on for a few secs(LED lights and all fans start working) then after 6-7 secs it turns of for 2 secs and again starts starts for another 6-7 secs and so on, so I finally decided to configure it tried all the tests with only cpu, heatsink fan, and power cables attached to my mobo and cpu then added attached one RAM stick and changed slots did the same with the other RAM stick checked my corsair PSU by using the pin technique and it worked so finally after deducing that my mobo is at fault I reassembled my pc and after doing so, when I hit the power button nothing happens as in(no LED's switch on, no fans running) it just remains the way it was, I checked all m connections 3-4 times and everything was connected and in place, so could it be that my CPU is dead or that my mobo went down, I can get the mobo replaced but if its a cpu problem im doomed! I read about tests that one could could check if CPU is dead or not by touching the cpu heatsink or the CPU directly without the heatsink and if they are warm it means that the CPU is working but I dont plan on using such risky methods so anyway to configure this problem?
P.S-I dont have a secondary pc to try it on nor can I borrow anyone else's pc to test it please help.