This part is a kind of semiconductor called 2SD1710.

Function of this product has SILICON POWER TRANSISTOR.

Manufacturers : SavantIC

Image and pinout :

Some of the text within the PDF file :

SavantIC Semiconductor Product Specification Silicon NPN Power Transistors DESCRIPTION ·With TO-3PML package ·High voltage;high speed ·High reliability. APPLICATIONS ·Ultrahigh-definition CRT display ·Horizontal deflection output applications PINNING PIN 1 2 3 Base Collector Emitter DESCRIPTION 2SD1710 Fig.1 simplified outline (TO-3PML) and symbol Absolute maximum ratings(Ta=25 ) SYMBOL VCBO VCEO VEBO IC PC Tj Tstg PARAMETER Collector-base voltage Collector-emitter voltage Emitter-base voltage Collector current Collector power dissipation Junction temperature Storage temperature TC=25 CONDITIONS Open emitter Open base Open collector VALUE 1500 800 6 5 50 150 -55~150 UNIT V V V A W SavantIC Semiconductor Product Specification Silicon NPN Power Transistors 2 [ ... ]

2SD1710 PDF Datasheet Download