If the fuse is blowing as soon as the power supply is connected to mains, I would check to see if any components of the power supply have failed in such a way that it would cause a short.
And for replacing it is it internal and external? I googled and getting mixed answers so will answer both. If its external I would find a power brick rated for the same specs as the original and if the connector is proprietary, rig it to the new one.
If Internal it looks like you can probably buy them from china for around $60 or find which component is causing the fault.
Good luck!