Part Number : 78M56A
Function :JRC NJM78M56
Manufacturer : Japan Radio Corporation
Pinout : 
Description
It is marked 78M56A and identified on the pcb as NJM78M56. it’s a TO-220 (mfr is JRC).
Datasheet PDF Download
Other datasheets in the file : 78M56A,NJM78M56