U can also insert a small piece of aluminum foil directly under the buttons that do not work. OR you can try rubbing a lead pencil directly on the bottom of the non functioning buttons and the area they contact on the pb.
It depends on what it is on, but I am seeing mention of a 1 POINT 6 (1.6) amp fuse so NO to a 15 amp fuse. Fuses are there to protect against shorts or overloads. The fix is not to put in a fuse that is 10 times bigger, or you burn out components or wiring. Fix the reason the fuse blew, normally take to an audio electronics engineer.
fuse (1.6A) 120vac
https://www.google.com/search?q=polk+audio+fuse
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