Mac Pro fan running blast after Starting up.

I've got a latest model of Mac Pro, and I'm having problem with it with the fan running at high speed a few minutes after I boot it up. I notice when this happens the computer seems to be unresponsive. The overall performance seems to be a disaster. I use this machine for video editing and having this kind of problem really gives me a hard time. Another issue also, when i try restarting, the computer cannot boot up when i choose the restart command. It kind a shut down command. I have to press the power button again to boot.

i have tried these steps.

- Resetting the SMC - unplug the power cable, wait for nearly a minute and press the power button for 25 sec while unplug. Give it another 20 sec and plug the power cable in. That doesn't help with the fan issue.

- Resetting the RAMs. - I've done this a couple of time but I don't think this is the problem.

I read one article on this problem and it says that it might cause with a dust, but their solution to the problem is to take the computer apart and have a clean in the inside. I'm a bit nervous with this new Mac pro with its compact body and bit a big challenge for me.

Anyone can assist me on this is an appreciation. If can be directed to a more specific issue to consider beside the ones I've tried that would be helpful.