I have looked at every capacitor or resistor but I don't know what this kind is called.

Does anyone know what this component is called? It's just a letter "W" in a blue square.

enter image description here

This board is from a Smart TV 55" grafic board.

  • 2
    \$\begingroup\$ Only one has a W, the other has an M! \$\endgroup\$
    – Tom V
    Commented Sep 26, 2022 at 19:33
  • 1
    \$\begingroup\$ W clearly means the part is white. The one below is marmite. \$\endgroup\$ Commented Sep 26, 2022 at 21:12

3 Answers 3


It appears to be a fast acting ceramic fuse rated for 7 amperes.

It looks very much like the Littelfuse "437 Series – 1206 Fast-Acting Fuse"

enter image description here

This table from the datasheet says code W is 7 amperes:

enter image description here

  • \$\begingroup\$ Waw. First time i see those kinds a fuses. Thanks. \$\endgroup\$
    – echo_Me
    Commented Sep 25, 2022 at 8:40
  • \$\begingroup\$ Note how they skipped M. I was gonna make a joke about it being M, but they thought of that... \$\endgroup\$ Commented Sep 26, 2022 at 5:54
  • 3
    \$\begingroup\$ This thing about soldering fuses to the PCB still puzzles me... (Yeah, showing my age here). \$\endgroup\$
    – Rmano
    Commented Sep 26, 2022 at 7:15
  • \$\begingroup\$ You can see the FS1 and FS2 markings on the PCB, which might be related. Would point towards a fuse I believe. \$\endgroup\$
    – jaskij
    Commented Sep 26, 2022 at 10:54
  • \$\begingroup\$ I wonder how they came up with the current ratings. They are neither R10 nor E12. \$\endgroup\$
    – jy3u4ocy
    Commented Sep 27, 2022 at 3:44

They are possibly this 7 amp fuse: -

enter image description here


Note the silkscreen markings "FS1" and FS2", indicating they are indeed fuses.


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