This document is a maintenance manual for Hisense VCRs. It mainly introduces the main board, servo circuit, video circuit, audio circuit, TV tuning, intermediate frequency demodulation circuit, OSD circuit, power circuit and other circuit components, pin functions, measurement methods, etc.
This document provides a detailed description of the VCR system control circuit, including the system controller, servo circuit, video circuit, audio circuit, TV tuner and demodulation circuit, OSD circuit, and power circuit. It lists the functions of each IC pin, the reference resistance and voltage values, and the testing procedures used.
The manual also explains how the circuit interfaces with the VCR's mechanical components, such as the tape loading motor, and how timing signals are generated and processed. Measurement data were obtained with a MF‑500 multimeter, and typical measurement error is noted to be within ±20%. This manual is written in Chinese.