This amp kept blowing fuses, so I thought "shorted power amp again," but it turns out the amp is fine. The ballast for the ultraviolet fluorescent bulb was hosed, causing the fuse to release at start-up. Instead of messing with another ballast (only available in the UK), I just installed a bank of black light UV LEDs, tapped off an internal DC supply. The should last a long time and the effect is just as good.