My computer has bad bad juju right now. D8

Basically, the thing won't turn on. When I first started it up this morning, it froze on the loading screen (little spinning wheel screen), so I did my usual of switching off the power and turning it back on again after a wait.

Except now it won't boot up at all. It sounds like the fans get going, but there's no startup noise. The power light flashes when I turn it on, but that's it.

I know that the outlets it's plugged into are fine. I tried troubleshooting, and it only got me as far as removing the back cover and fan and not noticing any lights or startup noises coming on when I tried it again. Is anyone out there enough of a mac genius to know what the problem is or how to fix it? Otherwise I'll be lugging this two-ton thing over to the nearest mac store in the hopes that SOMEONE will know how to fix it.

PLEASE HALP F-LIST D8