No power up on GA-SIMLFS motherboard

[Laidback and retired]

Can anyone help please? The only way I can get any life out of the Motherboard is to remove the CPU 4 block connector that powers the CPU, in this case an Intel 1.7 ghz. The motherboard led lights and the CPU fan works. When I refit the CPU connector the CPU fan attempts to start but then everything is dead.
I have tried removing the battery, cleared the CMOS taken off all ancillaries refitted memory modules and fitted a new power supply. I have now run out of ideas except replacing the motherboard in case there is a crack.
 
 

[Dark Mantis]

I think that it is probably a dead motherboard but I would try a few things first. Remove the heatsink and fan assembly and then the processor. Then refit them all carefully with paste. Remove and refit the ram modules. Try and reboot after fittinmg the 12v 4pin connector.