Can you please explain what you mean by "dead"? Are the lights still on in the front of the amp? Do the tubes still glow?
I have seen people not have the power cord in the back of the amp all the way.........
It could be very simple or very complicated.
You have done the right thing so far. If the power is completely out and no lights are coming on at all check your power source, then the power cable, then the fuse....keep working in this direction until you rule out certain things.
Even if the fuse does not look blown, it may be. If you have a replacement try it out. I always keep spares because this is the easiest thing to fix and I would be really ****** if it happened at a gig and I didn't have a 50 cent fuse.
If the power is on, check your speaker cable, your guitar chord, the input jack on your guitar....... keep going......
Post back with answers.
It could also be a tube. There are only 4 tubes total. If you have the money I would go buy replacements. If this fixes your problem you are good to go and you can test each individual tube to find out which one(s) was not working. If it doesn't fix your problem then you now have back-up tubes for when you need them.
Worst case scenario is your transformer is blown and you will need to get the amp repaired. If you just got it recently you might be able to return it to the seller and get a replacement.