This part is a kind of semiconductor called A2031.

Function of this product has 2SA2031.

Manufacturers : Sanyo Semiconductor Corporation

Image and pinout :

Some of the text within the PDF file :

Ordering number : ENN6586 2SA2031 / 2SC5669 PNP Epitaxial Planar Silicon Transistor NPN Triple Diffused Planar Silicon Transistor 2SA2031 / 2SC5669 230V / 15A, AF100W Output Applications Features • • • Package Dimensions unit : mm 2022A [2SA2031 / 2SC5669] 3.5 Large current capacitance. Wide ASO and high durability against breakdown. Adoption of MBIT process. 15.6 14.0 2.6 3.2 4.8 2.0 1.6 2.0 20.0 1.3 1.2 15.0 20.0 0.6 1.0 1 0.6 2 3 1.4 Specifications 5.45 5.45 1 : Base 2 : Collector 3 : Emitter SANYO : TO-3PB Note*( ) : 2SA2031 Absolute Maximum Ratings at Ta=25°C Parameter Collector-to-Base Voltage Collector-to-Emitter Voltage Emitter-to-Base Voltage Collector Current Collector Current (Pulse) Collector Dissipation Junction Temperature Storage [ ... ]

A2031 PDF Datasheet Download