Time to take it all out of the chassis and test a bare bones system with a minimal amount of components: mobo, cpu w/cooler, ram, kbd, mouse, system drive (leave gpu out if integrated graphics is available). If it works, add more components one by one to see if/when it fails. Also, test the voltage of the cmos battery if you can - it should be around 3 volts. I have heard of mobos that won't boot up if the battery is bad.
PSU is compatible. Try the 1st RAM stick by itself in each of the slots, and then try the 2nd RAM stick in each of the slots. If that doesn't work then it's probably not the RAM, so you either have a motherboard or CPU issue. The fact that your fans don't start spinning sort of makes me lean towards motherboard issue. Would probably need to RMA it.