This post explains for the transistor.

The Part Number is C3619, 2SC3619.

The function of this semiconductor is 300V, NPN Transistor.

Manufacturer: Toshiba Semiconductor

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Description

A silicon NPN triple-diffused type transistor refers to a specific type of NPN (Negative-Positive-Negative) bipolar junction transistor (BJT) that is fabricated using silicon as the semiconductor material and employs a triple-diffusion process in its construction.

The term “triple-diffused” refers to the manufacturing technique used to create multiple diffused layers within the transistor structure. Diffusion is a process in semiconductor fabrication that involves introducing impurity atoms into the silicon material to modify its electrical properties.

In a triple-diffused transistor, there are three distinct diffusion regions within the transistor structure, each with a different impurity concentration. These diffusion regions are typically the emitter, base, and collector regions […]

Absolute maximum ratings ( Ta=25°C )

1. Collector to Base Voltage: Vcbo = 300 V
2. Collector to Emitter Voltage: Vceo = 300 V
3. Emitter to Base Voltage: Vebo = 7 V
4. Collector Current: Ic = 100 mA
5. Collector Dissipation: Pc = 1.5 W
6. Junction Temperature: Tj = 150°C
7. Storage Temperature: Tsg = -55 ~ +150°C

Applications:

1. High Voltage Switching and amplifier
2. Color TV horizontal driver
3. Color TV chroma Output

C3619 Datasheet