oh no..did i mess up my amp

I was trying to find the noisy tubes in my tubed monoblocks by switching one tube and another..until one amp just went dead and I check the fuse at the back and it was blown..
before i do anything and make things worst ..i need your input on what to do..
change the fuse and see if it works? change the tube that did it?

did you allow your amp to cool down before shutting down and re-powering? I always allow at least 10mins between on/off cycles.
I did not allow the amp to cool down..
I would suggest letting the amp cool down, change tube, replace fuse, turn on.