Wikipedia:Reference desk/Archives/Science/2021 December 23

= December 23 =

Mysterious button failure
I have a Bosch Classix7 tumble drier whose on/off button is described as "sensitive and only needs to be touched lightly". It has always worked fine for me at a fingertouch, but recently my wife has been unable to get it to operate from fingertip, palm, wrist or elbow. So two questions - what is the principle of operation, and why should one person in particular stop being detected? →2A00:23C6:AA07:4C00:653B:7F45:D8C3:58A9 (talk) 15:29, 23 December 2021 (UTC)
 * The user manual found here advises what to check if the dryer does not start: Is the Start/Stop button selected? Door closed? Programme set? Ambient temperature greater than 5 °C? It also gives British and Irish telephone numbers for after-sales service. Philvoids (talk) 20:00, 23 December 2021 (UTC)
 * (OP) I thought that my query was clear, and I already have the user guide referred to. The device works for me by touching the "sensitive" button, but under identical conditions not for my wife. So I was asking if anyone knew what aspect of human presence (capacitance? heat? other?) was detected, and could offer a reason why it worked for one person but, from fairly recently, not for another. That's why the question is on the Science, rather than Miscellaneous, Desk.

→2A00:23C6:AA07:4C00:ED34:BB9A:F62A:8F7F (talk) 21:51, 23 December 2021 (UTC)
 * So it still works for you? If so this is a capacitive sensor and her skin isn't triggering it. Fun fact, I've had the same thing happen to me with an LG clothes dryer. After poking around for a moment, it looks like people have dubbed this kind of thing "zombie finger". A Web search for "zombie finger touch" should give results discussing this and things to try. --47.155.96.47 (talk) 01:46, 24 December 2021 (UTC)
 * Thanks. Using a screen stylus seems to work. →2A00:23C6:AA07:4C00:752D:3A97:9F33:54C9 (talk) 12:11, 25 December 2021 (UTC)