The Roanoke controller (same as yours except for programming) on the Memphis will energize the igniter if it senses a certain drop in temperature over a certain time. At very low tmps ~ 180º - ~ 220º ish, the
igniter stays off unless the lid is left open for a minute or so. At higher temps ~ 350º up, it is faster. ~ 500º it's almost instant: open the lid + the igniter comes on. When it comes on, it stays on for close to 7
minuits. When opening the lid, depending for how long I intend to have it open, I'll drop the temp setting to its lowest setting. That generally gives me time to do what I have to + get the lid shut averting an
other igniter cycle. My intent is to extend ignitre life.
After that long ramble, what may have happened to you is: The igniter shorted to ground just after it had ignited the pellets and the power to it from the controller had been switched off. After that when you
opened the lid, the pit temp dropped to where the controller felt a reignite was in order energizing the igniter circuit only for power to be sent to ground resulting in a circuit overload = burnt fuse.