# Identify a broken component

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

• That might be an SMD fuse. – Vladimir Cravero Dec 29 '15 at 13:05
• What did you do to the poor little thing to blow the lid off? – jippie Dec 29 '15 at 13:06
• Don't see why an SMD fuse would need a guard ring... oscillator resonator MAYBE but more likely some kind of sensor ... vibration perhaps? the odd mounting angle must be significant. Do both sensors point towards the platter centre? – Brian Drummond Dec 29 '15 at 13:12
• I bet the guard trace connects to a buffered output ... probably one of the SOT23 pins. – Brian Drummond Dec 29 '15 at 13:14
• Be aware that any of the parts it could be (see also Olin's answer), due to prior elimination steps above, are very unlikely to die at all, let alone in such a violent way. So you must be absolutely aware of the high likelihood that something else broke first, over-stressing this part. – Asmyldof Dec 29 '15 at 14:15