power supply unit look as if its dead

I imagine from where you bought it..if not you could email site sponsor and see if anything could be done

I would assume Openbox....but what model?

Either way from original supplier or google it 'openbox psu' and a well known Asian site should/will come up that should help you!

make sure it is really dead by measuring the voltages out.
A clone kill will show symptoms like a dead power supply but the power supply is fine.