Hp pavilion led lights up, nothing else - possible motherboard issues?

[Friedcomputerz208]

So I took apart and cleaned my laptop. I thought it would go smoothly since it had worked last summer. However now I'm stuck in a situation where the power led goes on, but the laptop is completely silent except for spinning the fan every few seconds. I've tried putting in the memory and the hard drive, nothing! It's not the only situation I've found myself in - earlier after I dusted the heatsink/fan it gave a warning that the fan wasnt working. I think I solved that though, since the computer is spinning the fan, but I am pretty concerned for my laptop, so does anyone please have advice. Any would be appreciated here

 

[Friedcomputerz208]

Still no answer, so can someone PLEASE help me?

I'm pretty sure it's with my motherboard, since it's starting for a split second then shutting down then repeating the process a few seconds later, while the power LED stays on the whole time

 

[Friedcomputerz208]

Some one please answer!

 

[vtec33]

check cpu for thermal paste and properly seated