Power switch is pressed, computer starts up, plays a sound effect through the internal speaker, power switch is pressed again and the computer shuts down. Recorded with a zoom h4n, placed inside the computer.
The kettle i have at home, going through a cycle until it switches off automatically when it reaches boiling level. I recorded it with my sony pcm-m10. Hope you find it useful!.
I switched on and off an old tape recorder. You can hear hum noise like an early synthesizer. The reason why it makes such noise is not sure, but that's the most important part of analog devices. Computer software cannot do that.
A recording of me typing on my havit kb390l mechanical keyboard with kailh low profile blue switches in them. The clicky sound is produced by a clickbar inside the keyswitch which produces an audible click on both the down and upstroke, differing from normal mechanical keyboards which tend to only click on the downstroke. Recording taken with my blue yeti nano.
Recording of me flipping an electric switch in the bathroom, when i pitched down & went on to process it with weirdo effects, sounded off an explosion like that of a depth charge.