Introduction
This manual provides detailed instructions for the Longines Master Collection 42mm Automatic Watch, Model L2.773.4.78.3. It covers the setup, operation, maintenance, and specifications of your timepiece to ensure optimal performance and longevity. Please read this guide thoroughly before using your watch.
Image: Front view of the Longines Master Collection 42mm Automatic Watch. The watch features a polished stainless steel case, a white textured dial with Arabic numerals, and elegant blue hands. It displays hours, minutes, small seconds, a 24-hour indicator, date, moon phase, and chronograph functions. The watch is fitted with a brown alligator leather strap.
Setup and Initial Winding
Your Longines Master Collection watch is equipped with an automatic mechanical movement (Caliber L687). It is powered by the motion of your wrist. If the watch has stopped or has not been worn for an extended period, it requires manual winding to start.
- Manual Winding: Unscrew the crown (if applicable) and pull it out to position 1. Turn the crown clockwise approximately 30-40 times. This will provide sufficient power reserve to start the watch. Push the crown back in and screw it down to ensure water resistance.
- Setting the Time: Pull the crown out to position 3. Turn the crown to set the hour and minute hands. Ensure the 24-hour indicator (at 9 o'clock) is correctly synchronized with the main time. Push the crown back in and screw it down.
- Setting the Date, Day, and Month:
- Date: The date is indicated by the half-moon central hand. Pull the crown out to position 2. Turn the crown to adjust the date.
- Day and Month: The day and month are displayed in apertures within the 30-minute counter at 12 o'clock. These are typically advanced by rotating the time past midnight. For quick adjustment, use the recessed pushers on the side of the case (refer to the diagram for locations).
- Setting the Moon Phase: The moon phase display is located at 6 o'clock. Use the dedicated recessed pusher on the side of the case to advance the moon phase disc. Consult a moon phase calendar for accurate setting.
Note: Avoid setting the date, day, or month between 9 PM and 3 AM, as this can damage the movement.
Operating the Chronograph
The chronograph function allows you to measure elapsed time. It is operated using the two pushers located on the side of the case, above and below the crown.
- Start: Press the upper pusher to start the central 60-seconds chronograph hand.
- Stop: Press the upper pusher again to stop the chronograph. The elapsed time will be indicated by the central 60-seconds hand, the 30-minute counter (at 12 o'clock), and the 12-hour counter (integrated with the moon phase display at 6 o'clock).
- Reset: After stopping, press the lower pusher to reset all chronograph hands to their zero positions.
Maintenance and Care
Proper care will preserve the beauty and functionality of your Longines watch for many years.
- Cleaning: Use a soft, dry cloth to wipe the case and crystal regularly. For more thorough cleaning, a slightly damp cloth can be used, but ensure the crown is fully screwed down to maintain water resistance. Avoid harsh chemicals or abrasive materials.
- Water Resistance: Your watch is water-resistant. However, it is crucial to ensure the crown and pushers are always fully screwed down or pushed in before any contact with water. Avoid operating the crown or pushers while the watch is wet or submerged. Water resistance is not a permanent characteristic and may decrease over time due to aging of gaskets or accidental shocks.
- Strap Care: The brown alligator strap is a natural material. Avoid prolonged exposure to water, direct sunlight, and extreme temperatures, which can cause drying, cracking, or discoloration. Clean with a soft, dry cloth.
- Magnetic Fields: Keep your watch away from strong magnetic fields (e.g., speakers, refrigerators, certain electronic devices), as these can affect the accuracy of the mechanical movement.
- Servicing: A mechanical watch requires periodic servicing to maintain its accuracy and reliability. Longines recommends a complete service every 3 to 5 years by an authorized Longines service center.
Image: The Longines Master Collection watch displayed on a wrist, highlighting its proportional fit and sophisticated aesthetic. The brown alligator strap complements the polished stainless steel case and white dial.
Troubleshooting
If you encounter any issues with your watch, please refer to the following common problems and solutions:
| Problem | Possible Cause | Solution |
|---|---|---|
| Watch has stopped or is running slow. | Insufficient power reserve. | Manually wind the watch by turning the crown clockwise 30-40 times. Wear the watch regularly to keep it wound. |
| Date/Day/Month not changing correctly. | Attempted to set during the restricted period (9 PM - 3 AM) or incorrect setting. | Avoid setting between 9 PM and 3 AM. If the issue persists, manually advance the time past midnight to check if the date changes. If not, consult an authorized service center. |
| Chronograph hands do not reset to zero. | Minor shock or internal misalignment. | This usually requires professional adjustment. Contact an authorized Longines service center. |
| Condensation under the crystal. | Loss of water resistance due to open crown/pushers or damaged gaskets. | Immediately take the watch to an authorized service center to prevent further damage to the movement. |
Specifications
- Model: Longines Master Collection L2.773.4.78.3
- Movement: Automatic mechanical, Caliber L687 (ETA A07.L01 base)
- Functions: Hours, minutes, small seconds with 24-hour indicator at 9 o'clock, date indicated by half-moon central hand, moon phase display with 12-hour counter at 6 o'clock, chronograph with central 60-seconds hand and 30-minute counter with day and month display at 12 o'clock.
- Case Material: Stainless Steel
- Case Diameter: 42mm
- Crystal: Scratch-resistant sapphire crystal with anti-reflective coating. Transparent case back with sapphire crystal.
- Strap Material: Brown Alligator leather with triple safety folding clasp and push-piece opening mechanism.
- Water Resistance: Water-resistant (specific depth not provided, generally 30m for dress watches, but always confirm with official Longines documentation).
Image: Rear view of the Longines Master Collection watch, featuring a transparent sapphire crystal case back that reveals the intricate automatic mechanical movement, including the oscillating weight engraved with the Longines logo and "Master Collection".
Warranty and Support
Your Longines Master Collection watch comes with a 5 Year International Warranty. This warranty covers material and manufacturing defects existing at the time of delivery of the purchased Longines watch.
The warranty does not cover normal wear and tear, damage caused by improper handling, lack of care, accidents, or unauthorized repairs. For full terms and conditions, please refer to the warranty card provided with your watch or visit the official Longines website.
For service, repairs, or any inquiries regarding your watch, please contact an authorized Longines retailer or service center. You can find a list of authorized centers on the official Longines website.