Component Identification (SOT23)

Thread Starter


Joined Aug 17, 2011
Hi all,

I'm trying find out what this component could be, its in a SOT23 package and presumably has the marking M21 like the one beside it (you can just make out an 'M' in the bit that's still there!). I've googled it but cant find anything conclusive. It blew presumably because of water ingress, its part of a CCTV camera and this particular circuit controls the IR filter movement.



Joined Jun 22, 2012
It will be a transistor possibly a fet or bipolar, you can buy a ready made cctv pcb module much easier to fix, chances are the tracks have corroded too. The IR module is just a solenoid that goes over the lens in daytime, operated by the photocell.