This part is a kind of semiconductor called 2SD1555.

Function of this product has NPN TRIPLE DIFFUSED(PLANAR SILICON TRANSISTOR).

Manufacturers : Wing Shing Computer Components

Image and pinout :

Some of the text within the PDF file :

2SD1555 NPN TRIPLE DIFFUSED PLANAR SILICON TRANSISTOR COLOR TV HORIZONTAL OUTPUT APPLICATIONS(Damper Diode BUILT IN) ! ! High Collector-Base Voltage(VCBO=1500V) High Speed Switching 2-16E3A ABSOLUTE MAXIMUM RATINGS (TA=25oC) Characteristic Collector-Base Voltage Collector-Emitter Voltage Emitter-Base voltage Collector Current (DC) Collector Dissipation (Tc=25 C) Junction Temperature Storage Temperature o Symbol VCBO VCEO VEBO IC PC Tj Tstg Rating 1500 1500 6 5 50 150 -50~150 Unit V V V A W o o C C ELECTRICAL CHARACTERISTICS (TA=25oC) Characterristic Collector- Emitter Cutoff Current(VBE=0) Collector Cutoff Current Emitter Cutoff Current DC Current Gain Collector- Emitter Saturation Voltage Symbol ICES ICBO IEBO hFE VCE(sat) Test Condition VCE= 1400 V , RBE=0 VCB= 800 V , IE=0 [ ... ]

2SD1555 PDF Datasheet Download