Seiko A828A – Technical Guide

The Seiko A828A is a digital quartz LCD movement developed in the early 1980s, designed for Seiko’s advanced world time watches. This module was part of a generation that offered more than just basic timekeeping—bringing dual time zone tracking, world city codes, alarms, and chronograph features to the wrist in an era when digital innovation was still new and exciting. The A828A became a key feature in Seiko's World Timer series, appealing to travelers and tech-oriented watch enthusiasts.

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Movement Overview

The A828A was considered a premium multifunction digital movement at its time of release. It was aimed at users who needed global time tracking, stopwatch features, and alarm functionality in one compact digital watch.

Core Functions:

• 12/24-hour time display

• World time (with city code selection)

• Second time zone (dual time mode)

• Daily alarm

• Hourly time signal (chime)

• Stopwatch (1/100 second, up to 60 minutes)

• Calendar (day, date, month, auto leap year correction)

• Light function (incandescent bulb in most models)

Battery Type: CR2016 lithium coin cell
Battery Life: Approx. 2 years (depending on backlight/alarm use)

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Display and Case Design

The A828A module was typically housed in mid-sized to large rectangular or tonneau-shaped cases, designed for optimal screen legibility and button ergonomics.

Display Features:

• Primary field: Hour, minute, second

• Secondary fields: City code, day of week, AM/PM or 24H indicator

• Mode indicators: Alarm, chrono, dual time, etc.

• All segments in liquid crystal (LCD) monochrome display

Case Features (common):

• Stainless steel or plastic/resin construction

• Integrated buttons for direct access to city/time modes

• Water resistance (varied by model, typically 30–50 meters)

• Caseback: Screwed or snapped, marked A828-xxxx

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Button Functions and Layout

Most A828A-powered watches feature four or five buttons, allowing fast access to travel and timekeeping functions:

• Mode (usually bottom-left): Cycles through Time → World Time → Alarm → Stopwatch → Calendar

• Set (bottom-right): Enters setting mode or confirms selection

• Advance/Start/Stop (top-right): Adjusts digits or operates stopwatch

• Light (top-left): Activates screen illumination

• City Select (varied position): Scrolls through city codes for time zone selection

The city code system was a highlight, offering fast toggling between preset global time zones—a rare feature in its time.

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Setting Instructions

Main Time & Calendar:

1. Press Mode to enter the main time screen.

2. Hold Set until the hour flashes.

3. Use Advance to adjust.

4. Press Mode to move through hour → minute → seconds → month → date → day.

5. Press Set to save and exit.

World Time (City Code Selection):

1. Press Mode to enter World Time.

2. Use City or Advance button to scroll through available cities (3-letter codes).

3. The display updates to show the corresponding time in that city.

4. Some models allow setting the local city as default.

Alarm:

1. Enter alarm mode with Mode.

2. Hold Set until digits flash.

3. Adjust hour and minute using Advance.

4. Press Set to confirm.

5. Toggle alarm and chime using Advance or a short press of Set.

Stopwatch:

• Enter stopwatch mode via Mode.

• Press Advance to start/stop.

• Press and hold Set to reset.

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Maintenance & Servicing

Though robust, the A828A requires careful handling during servicing due to its vintage circuitry.

Service Notes:

• Use CR2016 battery; change every 2 years

• Perform an AC reset after battery replacement (bridge AC pad to battery with tweezers)

• Avoid static electricity or strong impacts to the LCD panel

• Replace case gaskets to retain water resistance

• Light bulbs (if present) may be dim or non-functional due to age—usually not replaceable

• LCD bleed or fading is a known issue in some vintage units and may not be repairable

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Notable Models Using A828A

• Seiko World Time A828-4010 / 4020 / 4030

  • Stainless steel rectangular or tonneau-shaped cases

  • Prominent city code markings

  • Integrated bracelets or rubber straps

• Seiko A828-6019 Flight Timer

  • Popular among collectors

  • Features "Flight Computer" markings and aviation-styled bezel

These models are now considered collectible vintage digital watches, prized for their retro tech appeal and functional global timekeeping.

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Final Thoughts

The Seiko A828A was a breakthrough movement in its time, bringing together world time features, dual timekeeping, and stopwatch functions into a durable and wearable digital watch. Today, it stands as a milestone in Seiko’s digital evolution—ideal for collectors, travelers, and anyone who appreciates vintage tech with timeless utility. Whether worn or displayed, an A828A-powered Seiko watch remains a distinctive piece of horological history.