When an outdoor gig is coming up I often dust off the lead sled and practice with it at low volume. To help refamiliarize myself with the amp. This may seem pointless but it does help and I like to check the amp after periods of not being used. The thing is for low level practice I switch of the fan. I never do this on stage of course. The switch is non standard as far as I can see. The amp is a Peavey Classic 400. Am I pushing my luck doing this? Things got a bit toasty yesterday nothing broken yet.....advice welcome.