Hopefully it is just a blown fuse.
However the hissing sound may be a symptom of a larger problem. It could also be just a coincidence it coincided with the cable swap.
I can elaborate more, if a fuse swap doesn't fix the problem.
Why did my amp just crash and burn ?
I just installed a new set of AQ Robin Hood Zero cables. A little hiss sound from the speakers prompted me to adjust the spade connecters just a little on the amp. Then low and behold , the amp just cuts off and currently appears dead as a doornail.
What just happened and needless to say this is an absolute bummer.