Fuses and confusion

I am slowly upgrading my system and I am looking at the changing of fuses step. I have the following in my system:  Sunfire TGA-7401, Marantz AV8805, Carver Load Invariant amplifier, Marantz Ruby, and a Vault 2i. My questions are 1). Which of these components have\use fuses 2). Does changing the fuses invalidate the warranty? 3). Are there videos on changing the videos or do you just pop the hood and start looking. Please feel free to point out issues that I am not aware of and whether this is even relevant under my circumstances. Thanks in advance.