I'm trying to identify a component I salvaged off a projection TV PCB. It's blue or cyan with three legs marked 270S. Unfortunately I can't figure out where I pulled it off the board from so I don't have the board marking or location to help.component picture

I didn't see continuity, capacitance, or diode drops between any of the three legs when I checked it with a multimeter.


1 Answer 1


Its almost certainly a Ceramic Resonator.

These are three terminal devices that have a similar function to a crystal when used in an oscillator circuit, but are much cheaper and consequently have poor tolerances. Unlike most crystals, the ceramic oscillator contains built-in capacitors, so the extra pin (usually the middle one) is ground.

The marking 270 will almost certainly indicate 27MHz. This is a very common frequency in TVs - being the reference frequency for both PAL and NTSC video standards.

The S could be tolerance information, or it could be a date code. As an EIAJ monthly code, S would be May 2010 or some multiple of 8 years either side of it (e.g. 2002 or 2018)

There is no manufacturer information, so it won't be possible to find the exact specifications, however something like Murata CSTLS27M0X51 would be a similar type of device.

  • \$\begingroup\$ There are other ceramic resonators in square-ish orange packages (and metal cased crystals) in quite a few places on these boards so that seems pretty likely to me. I'm leaning toward not saving it given I can't find any datasheet for it and I don't have any projects planned I would use it in. Even the sketchy sites don't seem to have anything. \$\endgroup\$
    – Jonathan
    Jun 28, 2020 at 16:30

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