First time I took the hot end out for cleaning and inspection, after the heater no longer worked I took a look. Pin has backed out of the connector! I think I need to put a small tie around the wires??
I believe you can easily cut the heat-shrink tubing, put back the pin in place, insert a new heat-shrink tubing and before to warm it you could fill it with a drop of hot glue so everything will stay in place forever.