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NM Timer switch making a buzzing sound

  • Last Updated:
  • Dec 7th, 2019 3:26 pm
Deal Fanatic
Jul 7, 2017
5641 posts
SW corner of the cou…

NM Timer switch making a buzzing sound

Never mind: seems to be a defective design. Will try to warranty it as it is a known issue (cheap capacitor placed next to a resistor)

A few months ago, I bought one of those push button timer switches (30/15/10/5/off buttons, in descending order). $5 from the Sally so I am not out too much.

What is happening (and why I think it got donated in the first place) is that it makes a buzzing sound when pressed on. Sounds comes and goes, somethings it comes on and goes off within a few seconds, and sometimes it stays on.

Is there something electro-mechanical in there that could do with a cleaning, lubrication or some other self fix?
Cream rises to the top. So does scum.
2 replies
Deal Addict
Jan 21, 2018
4321 posts
The type of buzzing sound you describe is probably a 60 Hz buzz from the power line frequency. It happens when a solenoid/transformer coil is generating a 60 Hz alternating magnetic field that's vibrating the component or the surface it's mounted on. There doesn't have to be anything loose, more likely something just has enough flex to allow it to vibrate. You can find it by pressing down on the components with coils and the surfaces around them until you find the spot where pressure makes the buzz diminish or stop. Sometimes you can just press on the outer case, but it you have to go inside of a box with live 110v power, make sure you use something insulated like a pencil with a rubber eraser to do the pressing. Once you've find the spot, you can usually figure out how to stop the buzzing: disconnect power and try something like indenting or bending the case a little, gluing something down better, putting a rubber isolator between the component and the nearby surface etc.