I'm taking apart a misbehaving USB hard drive, and I've spotted a broken component on the PCB for the hard drive itself. Fortunately, there appears to be an intact, identical component on another part of the board, but I can't identify it.
The code on the top isFBD
(sorry for the awful phone picture), it appears to have two connections, has been deliberately surrounded by a ground trace, and is 4.9 x 2.3 mm
Best Answer
That is a piezoelectric ceramic shock sensor / acceleration sensor, likely made by muRata. I've seen up to 3 of them strategically located on hard drive boards. They are labeled as "SK" on WD PCBs, but aren't labeled on Maxtor HDs. Here are links for info and 2 datasheets:
https://www.murata.com/en-us/products/productdetail?partno=PKGS-00GXP1-R
https://www.murata.com/en-us/products/productdata/8797617225758/00GXP1-E.pdf?1452655830000
http://www1.futureelectronics.com/doc/MURATA/PKGS-00LD-R.pdf