Identifying small SMD actives can be a royal pain. The markings are often not the actual part number and manufacturer logo but an obscure code that's not unique to a part. You pretty much have to guess from the circuit what the part's function is, then figure out exactly what the package style and size is called (and there are often several different names for the same package). Then you start digging through datasheets to hopefully find something that matches the pinout and markings of your part. You can get lucky, or it can take hours for just one part.
U2 in this pic took me hours. It says 1F, and the "U" designation points to it being an integrated circuit, so that's what I was looking for. It turns out it's almost certainly a dual NPN transistor in a tiny 6-pin case. Part of what looks like an overvoltage protection scheme for the 9VDC input. Then why not call it Q something if it's a transistor (even dual), like the other Q's on board? The big 8-pin Q2 in front of U2 is clearly a transistor, for example (MOSFET), even though it really looks like an IC.
