I need to know the specifications of the transistor Q5 with top marking BC RJ
Tracing the circuit, I got:-
The biasing of Q5 suggests it is a PNP bipolar transistor. The resettable fuse rating of 0.3 A indicates that the transistor must be rated for >0.3 A, and the rating of EC2 suggests a voltage rating of 16 V or higher. The package appears to be SOT89.
I did a Google image search on "PNP SOT89" looking for a marking code similar to "BC" and found an On Semi 2SB1302 with code "BJ". I then searched On Semi's website for other similar transistors, and found the marking code order was the same as the listing order. This suggested that "BC" should correspond to 2SB1120. Finally I Googled that part number and got this:-