Seiko S820A Digital Watch Parts Catalogue & Technical Guide

Parts catalogue and technical guide for the Seiko S820A digital wristwatch, providing complete specifications for the S820A module. The guide covers the Nematic Liquid Crystal display with integrated time and calendar functions, including automatic date sequencing from 1993 to 2042. The module incorporates a temperature graph feature alongside a dual-mode thermometer (manual and automatic measurement from -20°C to +50°C), a chronograph with tachymeter capability displaying up to 10 hours in 1/1000 second resolution, and dual independent alarms. Technical specifications detail module dimensions at 34.3 mm outside diameter and 7.3 mm height, the Multiplex driving system architecture, and battery performance using Matsushita CR2025 cells rated for 2-year service life at 3.0V nominal voltage. Monthly rate accuracy is specified at better than 20 seconds deviation. Additional operational features include selectable sound control, battery depletion indicator, and an illuminating light panel for display readability. This workshop manual serves as an essential reference for service technicians, repair professionals, and parts identification, with complete component breakdowns and assembly details throughout.