Amp blowing fuses

I have a BAT VK-200 amp(purchased used 8 mos ago) and a BAT VK-31se(recently purchased new). 2 weeks ago I came home, put on an album-no sound. I pulled the amp and inserted my old b&K ST-140 mono blocks. When I turned them on one was OK but the other had a loud hum through the speakers, I switched interconnects and it went away. I called BAT and talked to Steve and he told me how to check and replace the fuses in the VK-200 amp. I did this and I was up and running in a few minutes. Could it be the bad interconnect that caused the fuses to blow? By the way these are 10 amp fast blow fuses. I just got the VK-31Se new a few weeks. This is my first piece of tubed equipment, is there something that I should be worried about with that unit? I will be calling BAT agian, but I would like to hear some of your thoughts and experiences.