Circuit component identification - label FB#

Hi all - troubleshooting and reworking a circuit board. I have a small flat SMT component labelled FB4, that appears open. All other components labeled FB# are dead short. This component is directly in the power path. When I jump the component by using my meter in amps mode - the board works as expected. I suspect its a simple fuse, but there exist other components labelled F# (F2, F4, etc) that are more obviously fuses.

This component has 2 leads only - no markings at all. Anyone seen this notation before (FB)?