A few days ago I’ve discovered that my hot air station, the [in]famous 858D, is not powering on. Upon opening it I found out that the fuse holder (panel-mount style) has its butt broken off. The remaining wire was happily flapping in a breeze inside the metal case. No burn marks, not melting signs, no fuse explosion — in fact the fuse is perfectly good. I was never touching the holder before, except for an attempt to open it after the device was no longer powering up. And that attempt was stopped as soon as I’ve noticed that the whole holder is rotating — it literally received a wiggle, like 1/8 turns, so not enough to damage anything. Since I was going to open the station anyway, I decided I can as well check that later. The photo shows the holder after I removed the second wire too, but you can get the idea. Now I have two questions.
What could’ve caused the damage? A random manufacturing failure? The factory used some weak plastic that degraded over a course of just a few years so much that it disintegrated by itself? Thermal stress? Phase of the moon?
The failure made one of the wires attached to the holder flying freely in the metal case. This was not the one of the power cord side — but we may safely assume this was just a coincidence. How can one design their device to account for that type of a failure? My first guess would be to always attach live wire to the side connector of the holder and putting shrink tube or glue on it. But what is the best practice in this case?