Hi,
how to find out on your own?
--> Internet search "SMD marking 2A"
is the most basic you could do. And most of the hits lead to the correct answer.
Then what else do you know?
* package: 3 pin. For me it looks like a "SOT-23" one. We can only guess, since we don´t have any information about the physical size. But you have.
* designator: "Q1" ... where the "Q" usually stands for a transistor.
--> so a refined search could be "SMD marking 2A SOT-23 transistor". I´ve checked the first 5 hits ... all lead to the same device.
****
For more complicated part search:
Always give additional informations:
* size of the device
* what´s the application (PCB) and in which section it is located (power input, signal input, signal ouptup, audio, fan control.... or whatever is known)
* always show much more of the PCB, so we can see where all the traces go to (what the pads are connected to)
Example: If we see an SOT-23 device with three pins, but only two of them are connected .. we immediately know it is not used as a transistor.
Thus we can focus on diodes, zeners ...
Klaus