1. ആമുഖം
This manual provides detailed instructions for the proper use and maintenance of your Casio G-Shock GW-7900B-1JF Tough Solar watch. Please read this manual thoroughly to ensure optimal performance and longevity of your timepiece. Keep this manual for future reference.

ചിത്രം 1.1: മുൻഭാഗം view of the Casio G-Shock GW-7900B-1JF watch, displaying its digital time, date, and various indicators.

Image 1.2: The Casio G-Shock GW-7900B-1JF watch worn on a wrist, showing its size and fit.
2 പ്രധാന സവിശേഷതകൾ
- Tough Solar Power: Utilizes solar panels to convert light into electrical energy, charging a rechargeable battery. This eliminates the need for regular battery replacement.
- Multi Band 6 Atomic Timekeeping: Receives time calibration signals from six transmission stations worldwide (Japan, North America, UK, Germany, China) to automatically correct the time.
- ഷോക്ക് പ്രതിരോധം: Designed to withstand impacts and vibrations, protecting the internal module.
- 200-Meter Water Resistance: Suitable for swimming, showering, and various water sports.
- Tide Graph & Moon Data: Provides information on tide levels and moon phases, useful for marine activities.
- Full Auto EL Backlight: Electro-luminescent backlight illuminates the display automatically in low light conditions when the watch is tilted towards the face.
- ലോക സമയം: Displays the current time in 48 cities (31 time zones) around the world.
- സ്റ്റോപ്പ് വാച്ച്: 1/100-second stopwatch with measuring capacity up to 23:59'59.99''.
- കൗണ്ട്ഡൗൺ ടൈമർ: Measuring unit of 1 second, countdown range of 24 hours.
- അലാറങ്ങൾ: 5 independent daily alarms and 1 snooze alarm.

Image 2.1: Illustration of the watch's shock-resistant structure, highlighting its durability.

Image 2.2: The watch submerged in water, illustrating its 200-meter water resistance capability.
3. പ്രാരംഭ സജ്ജീകരണം
3.1 Charging the Watch (Tough Solar)
Your watch is powered by a solar cell and a rechargeable battery. To ensure proper operation, expose the watch face to light regularly. The watch will charge even under fluorescent light, but direct sunlight is most efficient.
- Place the watch where its face is exposed to bright light.
- Avoid covering the watch face with clothing or other objects.
- The "CHG" indicator will appear when charging. The "P" indicator signifies full charge.
Note: Prolonged use in darkness or storage in a dark place can deplete the battery, leading to incorrect timekeeping or loss of functions.
3.2 Receiving Time Calibration Signals (Multi Band 6)
The watch automatically receives time calibration signals to maintain accurate time. Manual reception is also possible.
യാന്ത്രിക സ്വീകരണം:
- The watch attempts to receive the calibration signal up to six times a day (five times a day for the Chinese calibration signal).
- For best reception, place the watch near a window at night.
- Ensure the watch is not covered by metal objects.
മാനുവൽ സ്വീകരണം:
- In Timekeeping Mode, hold down the "ADJUST" button for about two seconds until the city code starts to flash.
- Press the "MODE" button repeatedly until the "RCVD" indicator appears.
- Press the "ADJUST" button to initiate reception. The watch will display "GET" while attempting to receive the signal.
- Once successful, "RCVD" will appear. If unsuccessful, "ERR" will be displayed.

Image 3.1: A radio tower, symbolizing the Multi Band 6 atomic timekeeping feature that receives time calibration signals.
3.3 Setting Home City and Daylight Saving Time (DST)
- In Timekeeping Mode, hold down the "ADJUST" button until the city code starts to flash.
- Use the "REV" (Split/Reset) and "FWD" (Start/Stop) buttons to select your desired Home City code.
- Press the "MODE" button repeatedly to cycle through settings: DST, 12/24-hour format, seconds, hour, minute, year, month, day, illumination duration, and power saving.
- Adjust each setting using the "REV" and "FWD" buttons.
- Press "ADJUST" to exit the setting screen.
4. പ്രവർത്തന നിർദ്ദേശങ്ങൾ
The watch features five buttons: "ADJUST", "REV" (Split/Reset), "FWD" (Start/Stop), "MODE", and "LIGHT".

ചിത്രം 4.1: വശം view of the watch, indicating the positions of the "ADJUST", "MODE", "REV", and "FWD" buttons.
4.1 നാവിഗേഷൻ മോഡുകൾ
Press the "MODE" button to cycle through the following modes:
- ടൈംകീപ്പിംഗ് മോഡ്
- വേലിയേറ്റം/ചന്ദ്രന്റെ ഡാറ്റ മോഡ്
- ലോക സമയ മോഡ്
- അലാറം മോഡ്
- സ്റ്റോപ്പ് വാച്ച് മോഡ്
- കൗണ്ട്ഡൗൺ ടൈമർ മോഡ്
4.2 സമയസൂചന മോഡ്
This mode displays the current time, date, and day of the week. It is the default mode.
- To toggle between 12-hour and 24-hour format, press the "FWD" button in Timekeeping Mode.
4.3 Tide/Moon Data Mode
This mode displays the tide graph and moon phase for a specific date and time.
- Enter Tide/Moon Data Mode by pressing the "MODE" button.
- Hold "ADJUST" to enter setting mode.
- Use "REV" and "FWD" to select the desired date and time for tide/moon data.
- Press "ADJUST" to exit.
4.4 വേൾഡ് ടൈം മോഡ്
View the current time in 48 cities (31 time zones) around the globe.
- In World Time Mode, use "REV" and "FWD" to scroll through city codes.
- To swap your Home City time with the World Time City time, hold down the "ADJUST" button for about three seconds.
4.5 അലാറം മോഡ്
Set up to 5 daily alarms and one snooze alarm.
- In Alarm Mode, use "REV" and "FWD" to select an alarm (AL1 to AL5, SNZ, SIG).
- Hold "ADJUST" to enter alarm time setting. The hour digits will flash.
- Use "REV" and "FWD" to change the hour. Press "MODE" to move to minutes.
- Use "REV" and "FWD" to change the minutes.
- Press "ADJUST" to set the alarm.
- Press "FWD" to toggle the alarm ON/OFF.
4.6 സ്റ്റോപ്പ് വാച്ച് മോഡ്
Measure elapsed time with 1/100-second accuracy.
- In Stopwatch Mode:
- Press "FWD" to start.
- Press "FWD" again to stop.
- Press "REV" to reset.
- For split times, press "REV" while the stopwatch is running. Press "REV" again to release the split and continue timing.
4.7 കൗണ്ട്ഡൗൺ ടൈമർ മോഡ്
Set a countdown from 1 second up to 24 hours.
- In Countdown Timer Mode, hold "ADJUST" to enter setting mode.
- Use "REV" and "FWD" to set the desired countdown start time (hours, then minutes, then seconds).
- Press "ADJUST" to set the timer.
- Press "FWD" to start or stop the countdown.
- Press "REV" to reset the timer to its start time.
4.8 Illumination (Backlight)
Press the "LIGHT" button to illuminate the display. The watch also features an Auto EL Light function.
Auto EL Light:
- Hold the "LIGHT" button for about three seconds to enable/disable Auto EL. An indicator will appear on the display when enabled.
- When Auto EL is enabled, tilting the watch towards your face (at an angle of 40 degrees or more) in a dark environment will automatically illuminate the display.
5. പരിപാലനവും പരിചരണവും
- വൃത്തിയാക്കൽ: Wipe the watch with a soft, dry cloth. For dirt or grime, use a soft brush and mild soap with water, then rinse thoroughly and dry.
- ജല പ്രതിരോധം: After exposure to saltwater, rinse the watch with fresh water and dry it completely. Do not operate buttons underwater.
- താപനില എക്സ്പോഷർ: Avoid exposing the watch to extreme temperatures (above 60°C / 140°F or below -10°C / 14°F) or sudden temperature changes.
- രാസവസ്തുക്കൾ: Keep the watch away from gasoline, cleaning solvents, aerosols, adhesives, paints, etc., as they can damage the resin case and band.
- സംഭരണം: When storing for long periods, ensure the watch is exposed to light periodically to keep the rechargeable battery charged.
6. പ്രശ്നപരിഹാരം
| പ്രശ്നം | പരിഹാരം |
|---|---|
| സമയം തെറ്റാണ്. |
|
| ഡിസ്പ്ലേ ശൂന്യമോ മങ്ങിയതോ ആണ്. |
|
| "ERR" appears during signal reception. |
|
| ബട്ടണുകൾ പ്രതികരിക്കുന്നില്ല. |
|
7 സ്പെസിഫിക്കേഷനുകൾ
- മോഡൽ നമ്പർ: GW-7900B-1JF
- സമയപരിപാലനം: Hour, minutes, seconds, p.m., month, day, day of the week.
- സമയ സംവിധാനം: Multi Band 6 (Automatic reception of time calibration signals from 6 global transmitters).
- ഊർജ്ജ സ്രോതസ്സ്: Tough Solar (Solar powered, rechargeable battery).
- ജല പ്രതിരോധം: 20 BAR (200 meters).
- ഷോക്ക് പ്രതിരോധം: G-SHOCK structure.
- ലോക സമയം: 48 cities (31 time zones), Daylight Saving Time (DST) auto/manual switching.
- സ്റ്റോപ്പ് വാച്ച്: 1/100-second; measuring capacity: 23:59'59.99''; measuring modes: elapsed time, split time, 1st-2nd place times.
- കൗണ്ട്ഡൗൺ ടൈമർ: Measuring unit: 1 second; countdown range: 24 hours; countdown start time setting range: 1 minute to 24 hours (1-minute increments and 1-hour increments).
- അലാറങ്ങൾ: 5 independent daily alarms; 1 snooze alarm; hourly സമയ സിഗ്നൽ.
- മറ്റ് പ്രവർത്തനങ്ങൾ: Tide Graph, Moon Data, Full Auto EL Backlight with selectable illumination duration, Battery level indicator, Power Saving function, Button operation tone on/off.
Note: Design and specifications are subject to change without notice. For the most current information, please refer to the official Casio webസൈറ്റ്.
8. വാറൻ്റിയും പിന്തുണയും
For warranty information, please refer to the warranty card included with your purchase or visit the official Casio G-Shock website. For product support, service, or replacement parts, please contact Casio customer service in your region.
ഔദ്യോഗിക കാസിയോ Webസൈറ്റ്: www.casio.com
Please note that warranty terms and service availability may vary by region.





