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You say the server's down.? If it's something like an HP Proliant you may be able to access it via the iLO (Integrated lights out)manger. If you can you'd be able to at least read some logs and try and reboot it from there. Are there other servers on the same site which you can access to prove the network? Any othrs missing which could tie the problem to a switch/router? Failing that, you may either need to get someone local to go to the server and check it visually or get in a car/bus/train/plane and do it your self!
If the power's out you'd need local people to tell you. You can't do anything remotely.