Seiko 2625A – Technical Guide (High Quality)

The Seiko 2625A is a compact quartz movement developed in the late 1970s to early 1980s as part of the Seiko 26xx series, designed specifically for ladies’ watches. It features three-hand operation (hour, minute, and central seconds) along with a date display, combining slimness and functionality with quartz accuracy. Its durable design and ease of maintenance made it a popular choice in Seiko’s elegant and minimalist women’s collections.

1. Technical Specifications

2. Key Features

• Three-hand display: Hour, minute, and central seconds

• Date display at 3 o'clock with quickset via crown

• Hacking function for precise time setting (seconds hand stops when crown is pulled)

• Compact and thin—designed to fit small-diameter ladies’ watches

• No day function, keeping the movement simple and energy-efficient

• Highly reliable quartz oscillator ensures long-term accuracy

• Low-maintenance construction with extended battery life

3. Calendar Operation

Setting the Time and Date:

1. Crown Position 0 (pushed in): Normal operation

2. Crown Position 1 (pulled one click):

   • Turn the crown to quickset the date (usually clockwise)

3. Crown Position 2 (pulled two clicks):

   • Set time by turning crown

   • Seconds hand will stop during time setting for accuracy (hacking function)

⚠️ Avoid quicksetting the date between 9:00 PM and 2:00 AM, as the calendar mechanism may already be engaged and could be damaged.

4. Movement Architecture

Key Components:

• Quartz oscillator (32.768 kHz)

• IC (integrated circuit) controlling the timing and step motor pulses

• Step motor driving a gear train to the hands

• Calendar mechanism under the dial with date ring, jumper, and quickset gear

• Time-setting system using clutch, sliding pinion, and stem

The 2625A uses a central seconds configuration and a traditional date ring layout visible through the dial window.

5. Battery Replacement

Procedure:

1. Open the case back carefully (snap-on or screw-down).

2. Use plastic tweezers to remove the old battery.

3. Check for corrosion at contact points and clean gently if needed.

4. Insert new battery (positive side up).

5. Check that the second hand begins moving within 15 seconds.

6. Set the time and date, and reseal the case (replace gasket if needed).

⚠️ Always use ESD-safe tools and handle movement components carefully to avoid static damage.

6. Troubleshooting & Repairs

7. Watch Applications

The Seiko 2625A powered a range of ladies’ quartz watches from the early 1980s, especially models featuring:

• Case diameters around 18–24 mm

• Date windows at 3 o’clock

• Domed acrylic or flat mineral crystals

• Elegant minimalist dials with applied indices

• Stainless steel or gold-tone cases with snap or screw backs

Case references include:

• 2625-0010

• 2625-7000

• 2625-0030

These watches were positioned as practical, accurate everyday wearers with a touch of sophistication.

8. Service Tips

• Do not lubricate the plastic gear train

• Clean any dust from the date ring and calendar spring

• Replace case and crown gaskets during service to restore water resistance

• Always confirm proper alignment of the date window before re-casing

• Avoid prying hands off too forcefully—parts are delicate

9. Conclusion

The Seiko 2625A is a reliable, compact quartz movement that brings full three-hand functionality and quickset date to vintage ladies’ watches. Its combination of precision, durability, and ease of use has kept it ticking for decades. With routine maintenance and battery changes, this little workhorse remains a fine example of Seiko’s mastery in quartz microengineering. Whether you’re servicing, restoring, or collecting, the 2625A is a movement worth preserving.