I've got a board with a couple of 6-pin SMT devices. They're marked 2Q and on the second line ow34 - the o is offset and might be a logo, or a pin 1 marker.
I can't find it in the SMD code book as 2Q (the only 2Q is a SOT32), but as 34 it could be a MUN5334DW1 complementary bipolar digital transistor
http://www.onsemi.com/pub/Collateral/DTC124XP-D.PDF. That would make sense circuit-wise too - it's used as a power output stage, like a class AB amplifier.
The markings don't seem to add up though. If it were the On Semiconductor part it should be marked 34M. (the . is part of the marking, meaning lead-free). Could it be a second-source ? or some other part entirely, such as a mosfet half h-bridge, which would also make sense in the circuit ?