Seiko N851 Instructions Manual

To set the time, pull the crown out to the second click position. Turn the crown to adjust the time. Once the correct time is set, push the crown back to its normal position.
Pull the crown out to the first click position. Rotate the crown to adjust the date. Ensure the watch is not set between 9 PM and 3 AM to avoid damaging the mechanism.
First, check if the watch needs a new battery. If the battery is fine, consider having it serviced by a professional to check for mechanical issues.
Use a soft cloth to wipe the watch. For more thorough cleaning, use a damp cloth with mild soap and water, avoiding the leather strap and the watch's crown.
The Seiko N851 is water-resistant to a certain depth. Check the specific model's water resistance rating before swimming and ensure the crown is securely pushed in.
It is recommended to have your watch serviced every 3-5 years to ensure optimal performance and longevity.
Store your watch in a cool, dry place, ideally in a watch box or case to prevent scratches. Keep it away from extreme temperatures and magnetic fields.
This could be due to exposure to magnetic fields or a need for servicing. If the issue persists, have a professional adjust the watch's movement.
Use a spring bar tool to remove the current strap. Insert the tool between the strap and the lug, compress the spring bar, and detach the strap. Reverse the process to attach a new strap.
For minor scratches, a professional polishing service may suffice. For deeper scratches, replacing the glass by a certified Seiko service center is recommended.