The machine wouldn’t start… then I found the “fuse sandwich”

Posted by filco86@reddit | talesfromtechsupport | View on Reddit | 77 comments

I got called to check a vending machine that was acting completely crazy. It wasn’t dead, but nothing worked properly. The controls were all over the place, it kept checking the boiler, but wouldn’t actually start anything.

It was a pretty big coffee machine, so I expected some clear fault. I start going through everything — power, wiring, pump, boilers, sensors — but nothing really made sense. No obvious issue, yet the machine was basically unusable.

So I start tracing everything back more carefully.

Eventually I get to the power input area and notice the fuse looks… off.

I pull it out, and that’s when it hits me.

It wasn’t really a fuse anymore. It was wrapped in aluminum foil like some kind of “fuse sandwich”.

Turns out the customer had “fixed” it instead of replacing it.

So instead of blowing like it should, it kept letting unstable current through, which ended up damaging the control board and messing with the machine logic.

What could have been a cheap fix turned into about a 400€ repair.

All because of a “quick fix”.