So I decided to dig out the RX-400A that I purchased new back in the day. Everything fired right up but the right channel was dead as a carp. It's never been opened up so thought it might be time, I hosed it down with deox and started with the easy stuff and hallelujah there's a blown fuse on that channel. I eyeballed it and it's a 1.5 amp FDK fuse. Googled around without much luck, doesn't seem to be any mention of FDK fuses. So I dug around in my old car stuff and found a 1.5 AGC and tried it. Eureka I'm back in the stereo business. My question is about the original FDK fuses. Are FDK's obsolete? been superseded by another type? Should I be using fast blow or slow blow? From what I could read there isn't a reason to not use a DC fuse in an AC device, but you shouldn't use an AC fuse in a DC device. At any rate the Rotel is working, at least for 15-20 minutes and I shut it down until I was sure about the correct fuses.