Minecraft wiki entry for Redstone_components, associated text: One way to cause a burnout is with a short-circuit – using a torch to turn itself off, which then allows the torch to turn back on, etc. For example, placing redstone dust on top of a block with a redstone torch on its side, then putting another block above the torch, causes the torch to power the top block, which activates the dust, which powers the first block, turning the torch off – this feedback loop causes the redstone torch to flicker and burn out. When putting a torch underneath a block, make sure that the block isn't adjacent to redstone dust or the torch can burn out.