1. Introduction
This manual provides detailed instructions for the operation and maintenance of your G-Shock Casio GA-100 Series Analog-Digital Watch, model GA100WD-1A. This timepiece is designed for durability and functionality, featuring shock resistance, 200-meter water resistance, and a combination of analog and digital displays.
Please read this manual thoroughly to ensure proper use and to maximize the lifespan of your watch.
Figure 1: Front view of the G-Shock Casio GA-100WD-1A watch. It features a black resin case and band, with a high-contrast white analog-digital dial. The dial includes two analog hands, three digital sub-displays, and various indicators for functions like speed, stopwatch, and day of the week. Four prominent buttons are visible on the sides of the case.
2. Watch Components and Button Operations
Figure 2: Side view of the G-Shock Casio GA-100WD-1A watch, highlighting the two buttons on the left side. These buttons are typically labeled 'ADJUST' and 'MODE' and are used for setting and navigating through watch functions.
Your GA-100 watch has four primary buttons and a light button. Refer to the diagram below for their locations and functions.
- A (ADJUST) Button (Top Left): Used to enter and exit setting modes, and to confirm settings.
- B (REVERSE) Button (Top Right): Used to scroll backward through settings or display options.
- C (MODE) Button (Bottom Left): Used to cycle through the watch's various modes (Timekeeping, World Time, Stopwatch, Timer, Alarm).
- D (FORWARD/START/STOP) Button (Bottom Right): Used to scroll forward through settings or display options, and to start/stop stopwatch or timer operations.
- E (LIGHT) Button (Front Bottom): Activates the LED backlight.
3. Initial Setup
3.1 Setting the Home City and Time
- In Timekeeping Mode, hold down the A (ADJUST) button until the city code starts to flash. This indicates the setting mode.
- Use the B (REVERSE) and D (FORWARD) buttons to select your desired Home City code.
- Press the C (MODE) button repeatedly to cycle through other settings: DST (Daylight Saving Time), 12/24-hour format, Seconds, Hour, Minute, Year, Month, Day, and illumination duration.
- Use the B (REVERSE) and D (FORWARD) buttons to adjust each setting as it flashes.
- After setting all desired values, press the A (ADJUST) button to exit the setting mode. The watch will automatically adjust the analog hands to match the digital time.
3.2 Analog Hand Adjustment (if misaligned)
If the analog hands do not match the digital time after initial setup or battery change:
- In Timekeeping Mode, hold down the A (ADJUST) button until the city code flashes.
- Press the C (MODE) button repeatedly until "H.SET" (Hand Set) appears on the digital display.
- Use the D (FORWARD) button to advance the minute hand clockwise until both analog hands point to 12 o'clock. The hands move quickly when held down.
- Press the A (ADJUST) button to confirm. The hands will then move to the current digital time.
4. Operating Modes
Press the C (MODE) button to cycle through the following modes:
- Timekeeping Mode: Displays the current time, day, and date. This is the default mode.
- World Time Mode (WT): Displays the current time in 48 cities (29 time zones) around the world. Use B (REVERSE) and D (FORWARD) to view different city times.
- Stopwatch Mode (STW): Measures elapsed time, split times, and two finishes.
- Press D (FORWARD) to start/stop.
- Press A (ADJUST) to reset while stopped.
- Countdown Timer Mode (TMR): A countdown timer with a settable range of 1 minute to 24 hours.
- Hold A (ADJUST) to set the timer.
- Press D (FORWARD) to start/stop.
- Alarm Mode (ALM): Features 5 daily alarms and a snooze alarm.
- Use D (FORWARD) to scroll through alarms (AL1 to AL5, SNZ, SIG).
- Hold A (ADJUST) to set an alarm time.
- Press D (FORWARD) to toggle alarm ON/OFF.
4.1 Using the LED Light
Press the E (LIGHT) button to illuminate the watch face. The watch also features an Auto Light Switch function, which can be enabled or disabled in the Timekeeping Mode settings. When enabled, tilting your wrist towards you will automatically activate the light.
5. Maintenance and Care
5.1 General Care
- Clean the watch regularly with a soft, dry cloth. For stubborn dirt, use a soft brush and mild soap solution, then rinse thoroughly and dry.
- Avoid exposing the watch to extreme temperatures, direct sunlight for prolonged periods, or strong magnetic fields.
- Do not operate buttons underwater.
5.2 Battery Replacement
The watch uses one LR44 battery. When the display becomes dim or functions become erratic, it may be time for a battery replacement. It is recommended to have the battery replaced by an authorized G-Shock service center to ensure proper water resistance sealing.
Figure 3: Back view of the G-Shock Casio GA-100WD-1A watch. The stainless steel case back is secured with four screws and features engravings such as "G-SHOCK", "SHOCK RESIST", "WATER RESIST 20BAR", "STAINLESS STEEL BACK", and the module number "5081".
5.3 Water Resistance
Your watch is water resistant to 20 BAR (200 meters). This means it is suitable for showering, swimming, and diving (excluding saturation diving). Always ensure the crown (if applicable, though not on this model) is pushed in completely before exposing the watch to water. Do not operate buttons while the watch is submerged.
6. Troubleshooting
- Analog hands do not match digital time: Perform the "Analog Hand Adjustment" procedure described in Section 3.2.
- Digital display is blank or dim: The battery may be low. Replace the battery as described in Section 5.2.
- Watch functions are erratic: A strong impact or magnetic field might have affected the watch. Try resetting the watch by pulling out the crown (if applicable) or performing a full reset if the module supports it (refer to full Casio manual for Module 5081). If issues persist, contact customer support.
- Buttons are unresponsive: Ensure the watch is not in a locked mode (not applicable for this model's basic functions). If submerged, wait until dry. If still unresponsive, seek professional service.
7. Specifications
| Feature | Description |
|---|---|
| Model Number | GA100WD-1A |
| Module Number | 5081 |
| Water Resistance | 20 BAR (200 meters) |
| Shock Resistance | Yes |
| Magnetic Resistance | Yes |
| Timekeeping | Analog and Digital (Hour, Minute, Second, PM, Month, Date, Day) |
| World Time | 29 time zones (48 cities + UTC), daylight saving on/off, Home city/World time city swapping |
| Stopwatch | 1/1000-second, measuring capacity: 99:59'59.999'', measuring modes: Elapsed time, lap time, split time, speed (0 to 1998 units/hour), distance input (0.0 to 99.9) |
| Countdown Timer | Measuring unit: 1 second, countdown range: 24 hours, countdown start time setting range: 1 minute to 24 hours (1-minute increments, 1-hour increments) |
| Alarms | 5 daily alarms (with 1 snooze alarm), hourly time signal |
| Illumination | LED light (Auto LED light, selectable illumination duration, afterglow) |
| Battery | 1 x LR44 (approx. 2 years) |
| Accuracy | ±15 seconds per month (without calibration) |
8. Warranty and Support
Your G-Shock watch is covered by a manufacturer's warranty. For specific warranty terms, duration, and service procedures, please refer to the warranty card included with your purchase or visit the official G-Shock website for your region.
For technical support, repairs, or genuine replacement parts, it is recommended to contact an authorized G-Shock service center. Unauthorized repairs may void your warranty.
Official G-Shock Website: www.gshock.com
