identificationpcbunits
I recently came across a symbol like this on a PCB: (forgive the use of Paint)
The component was marked as being 0.1 (symbol).
You can just make it out in the centre of this photo:
It's a capacitor, so I'm guessing it's perhaps measuring farads, but surely then an F would have been used… What is it measuring?
I'll be an outlier here and guess that it's a (blown) 0.5A "pico fuse" style fuse, and I'd be pretty sure if it's the first thing connected to the mains wire.
Break it apart you'll quickly see what its made of (and can easily rule out inductor, if there's no copper wire inside). A fuse and a resistor may not be easy to distinguish.
If it is a fuse, and if it's blown, there's a significant chance other stuff is blowed up good. Poke around and check the power semiconductors and diodes.
Edit: For those who have little experience with Asian manufacturing, here's an example of the type of fuse, mostly supplied by Chinese manufacturers:
The 'cement' finish in the OP's photo (rather than the smooth lacquer you'd expect on an inductor or resistor) is another not-so-subtle clue as to the functionality.
My supposition:
It is a ferrite bead, and it is being used, along with the capacitor next to it, as a small filter on the power supply.
It is a 'non critical' component and only really has any affect when you're using a noisy power supply.
You should be able to replace it with pretty much any 0603 ferrite bead. Lower DC resistance is better as it reduces the voltage drop across it.
You could even replace it with a blob of solder to get it working again.
Best Answer
I am thinking that セ is used by the Japanese as shorthand for セラミック (ceramic). That is a ceramic disk capacitor, of course.
セラミック is a Katakana transliteration of the English word ceramic, and sounds like cer-ram-ique-ah.