Pc wont boot with new cpu

[Hlias Anton]

hello guys i will describe my problem from the start to have full info about my problem.

i had a quad q8300 on my pc, 1 day i tried open my pc and its didnt boot, the fans working but nothing was happening. so i changed the cpu with an old 1, a celeron, and the pc started normal, so i thought ok the cpu was the problem.
1 week ago a friend gave me an E8500 cpu, and again my pc didnt start with that cpu, the fans start but nothing happening. the cpu is working i tested it on my brother pc and its fine, he is using it now. So i took my brother cpu an e4500 and my pc was working.
i took from another friend 3 more cpu(and the 3 working in other system). 1 q9300 and 2 q6600.
and noone works in my pc.

so the summary is, my pc works with: celeron, e4500
and dont work with e8500, quad 9300 and 6600
+ my first cpu was the q8300 that i burned.

after reading a lot of threads on google i tried the next:

update the bios in last version and after in the version that the cpu needs, clear cmos. removed hd gpu ram sand i put them back 1 by 1.

my motherboard is gigabyte GA G31M s2L and it supports all the cpus that i listed above.
so any idea why my pc dont start with that cpus?

 

[logainofhades]

Sounds like the motherboard is on its way out.

 

[Hlias Anton]

i will take new mobo in 2 days, and i hope all to be fine.

 

[Hlias Anton]

Sounds like the motherboard is on its way out.

ok i took new mobo and all cpus work fine now. Any idea what could be the problem in the old mobo?

 

[logainofhades]

Look for any leaky or bulging caps.