The Seiko A229A is a digital quartz movement developed in the early 1980s, part of Seiko’s A-series LCD (liquid crystal display) technology. The A229A is notable for powering world time watches, allowing the wearer to view the time across multiple time zones—an advanced feature during its era. Designed for travel, practicality, and accuracy, the A229A remains highly collectible among vintage digital watch enthusiasts due to its multifunction display and unique layout.

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Technical Specifications

• Caliber Number: A229A

• Movement Type: Quartz (Digital LCD)

• Display Type: Liquid Crystal Display, 7-segment format

• Primary Functions:

  • Local Time (12-hour or 24-hour selectable)

  • World Time (with pre-set cities or time zones)

  • Calendar (Day and Date)

  • Daily Alarm

  • Stopwatch (1/10-second resolution)

• Backlight: Not integrated in the module (may be present as a separate case-mounted light)

• Battery Type: SR1120W (1.55V silver oxide)

• Battery Life: Approximately 2 years

• Accuracy: ±15 seconds per month

• Module Dimensions:

  • Width: ~26 mm

  • Height: ~22 mm

  • Thickness: ~5 mm

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Key Features and Display Layout

The A229A movement was used in Seiko digital watches marketed with World Time or World Timer branding. These watches typically feature:

• Dual-line display:

  • Top line shows the city name or time zone abbreviation

  • Bottom line shows HH:MM:SS with optional PM indicator

• Day of the week and calendar date appear as secondary information

• Indicator segments such as “AL” (alarm), “ST” (stopwatch), “WT” (world time), or “24H” for military time

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Operating Modes

1. Local Time Mode

• Time displayed in hours, minutes, and seconds

• 12-hour or 24-hour format selectable

• Also shows day of week and date

• Typically the default mode on startup

2. World Time Mode

• Displays the current time in any of 24 major global cities

• City code or name (e.g., NYC, LON, TYO) shown on upper part of screen

• Automatically calculates offset from local time

3. Alarm Mode

• Daily alarm setting with hours and minutes

• Audible buzzer alerts at the set time

• Alarm ON/OFF toggle option available

4. Stopwatch Mode

• Measures elapsed time up to 59 minutes, 59.9 seconds

• Resolution: 1/10-second

• Start, stop, and reset with corresponding buttons

5. Set Mode

• Accessible in each of the above modes to adjust values

• Includes setting for 12/24-hour format, alarm, and calendar

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Button Configuration (Typical)

Most A229A watches feature four buttons, usually located around the case:

• Button A (Top Left) – Mode selector (cycle through Time, Alarm, Stopwatch, World Time)

• Button B (Bottom Left) – Select digit/field, toggle between 12/24-hour format

• Button C (Top Right) – Advance values, start/stop stopwatch

• Button D (Bottom Right) – Reset stopwatch, confirm settings, toggle alarm

City selection for world time is typically managed using Button B or C, depending on the sequence.

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Battery Replacement and AC Reset

After battery replacement, a reset is required for proper module function.

Reset Procedure:

1. Open the case back using a case opener

2. Remove the depleted SR1120W battery using plastic tweezers

3. Insert a new battery with correct polarity

4. Locate the AC (All Clear) contact on the PCB

5. Use metal tweezers to short the AC terminal to the battery’s negative terminal (case or contact spring) for 1–2 seconds

6. LCD will flash all segments and return to default local time mode

Skipping this reset may result in no display or improper operation.

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Maintenance Notes

• No lubrication required – dry electronic module

• LCD aging may cause faded segments or ghosting; usually not repairable

• Piezo buzzer may weaken with corrosion—clean contacts if alarm is faint or silent

• Buttons may need internal contact cleaning if unresponsive due to oxidation

• Keep dry – most models using the A229A were only splash-resistant

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Watch Models and Usage

The Seiko A229A powered several World Time watches with prominent city bezel markings or LCD city selectors. Case materials varied from resin to stainless steel. These watches were ideal for business travelers, pilots, and those coordinating across time zones.

Typical reference numbers include A229-5000, A229-5019, or similar. These models were globally distributed and remain collectible for their iconic 80s digital styling and functionality.

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Conclusion

The Seiko A229A movement is a fine example of Seiko’s early innovation in world time digital watchmaking. Its compact, logical design, travel-focused functions, and durable construction made it a favorite among globetrotters of the 1980s. Today, it remains a standout piece in vintage digital collections, especially for those who appreciate practical features wrapped in retro tech.

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