Dell Vostro motherboard broken?

[kertp]

I changed thermal paste of Dell Vostro, but unfortunately it doesnt turn on. All I can hear is a quiet click while pressing the power button. The leds dont light up and fans dont spin at all. Does this mean that the motherboard is broken?

 

[cin19]

Make sure you did connect the cooler fan connector into the MB.

 

[kertp]

I already checked it and it seems to be okay.