I worked on an dead AL811H for a friend and was surprised to see a blown 1 amp 250v fuse in the HV line, in front of a glitch resistor. Surprised because the whole idea of the glitch resistor was to absorb any HV spikes and to fall on the knife, so to speak, and thereby save other more valuable components. So why the fuse? A fuse would have been the first thing one would think of instead of a resistor when the idea came about some years ago. In this case, there's now a component whose only task is to save the glitch resistor. So, we now have three ways of stuffing the fire: fuse, glitch resistor, or both. But something's redundant here. The amp now works fine with a a new fuse, but I'm suspicious.