One component on this board has eluded me.  It is marked S544 horizontally at top,  the letters MEX down the right an J6 at the bottom.  The T logo is stylized with a swooping top.  Searching for the manufacturer has eluded me as well.

  [![enter image description here][1]][1]

I appreciate any assistance identifying this component.



  [1]: https://i.sstatic.net/gipB3.jpg