Seiko Cal. 7G21A Parts Catalogue and Technical Guide
Seiko Cal. 7G21A parts catalogue and technical guide for this precision quartz stepping motor movement. Provides complete specifications including 2.2 mm height and 15.5 mm case diameter, with detailed coverage of the load-compensated stepping motor, LED illumination circuit, and electronic reset mechanism. Features exploded diagrams showing all movement components and their relationships. Covers battery requirements (1.55V for primary operation, 3.0V for bulb illumination), step-by-step disassembly and reassembly procedures with proper technique, lubrication specifications using Moebius A oil, SEIKO Watch Oil S-6, and silicone oil 500,000 c.s., and electrical testing parameters for coil block resistance and current consumption measurement. Essential reference for service technicians working on this caliber.
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Document Details
- Format
- Pages
- 4
- Size
- 96.6 KB
- Category
- Watchmaking