This part is a kind of semiconductor called C3619.
Function of this product has 2SC3619.
Manufacturers : Toshiba Semiconductor
Image and pinout :

Some of the text within the PDF file :
High voltage switching and amplifier applications.
Color TV horizontal driver applications.
Color TV chroma ouput applications.
Featurs
1. High Voltage : Vceo = 300 V
2. Small Collector Output Capacitance : Cob = 3.0pF ( Typ.)
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C3619 PDF Datasheet Download