dismantled a rolling demaree of 2 brood boxes, 4 supers in order to swap frames from top with bottom as 'rolling'
put it all back
forgot to put q back in bottom box
let her walk in front door rather than open up again
this happened to mine
easy fix i reckon
take the bottom off and the connection (red wire) from the heating terminal will have dropped off when knocked
worth gently clamping it back on to withstand minor knocks in future