This post explains for the semiconductor C3421.
The Full Part Number is 2SC3421.
The function of this semiconductor is Silicon NPN Epitaxial Transistor.
The manufacturers of this product is Toshiba Semiconductor.
See the preview image and the PDF file for more information.
Preview images :
Audio Frequency Power Amplifier Applications
• Complementary to 2SA1358
• Suitable for driver of 60 to 80 watts audio amplifier
• High breakdown voltage
Absolute Maximum Ratings
1. Collector-base voltage : VCBO = 120 V
2. Collector-emitter voltage : VCEO = 120 V
3. Emitter-base voltage : VEBO = 5 V
4. Collector current : IC = 1 A
5. Base current : IB = 100 mA