While she is older than 18 years old, she is not allowed to smoke 🙂 .
So I started to look for the reason why she did.
First I measured the resistance between the resistor that smoked (R406) and ground.
It was only 0.2 Ohm, A little to low.
So I checked the schematics and noticed that the capacitor C401 and C402 are also in the circuit.
As Capacitors die after some time, I removed them from the circuit board.
When I checked the capacitor C401 it only measured 0.2 Ohm, while C402 was somewhere in the mega Ohm.
So I found the reason why R406 was smoking.
I’m now waiting the ordered capacitor and resistor.