CASIO G-Series Watch User Manual (Modules 3750, 3751, 4314)
Model Numbers: G-300, G-306, G-313, G-353, G-350, G-540, G-550, G-740, G-741
Module Numbers: 3750, 3751, 4314
Important Information
Battery
The battery installed at the factory may discharge during shipping and storage. If you notice signs of low power (e.g., dim display), have the battery replaced by an authorized CASIO service center or dealer.
Water Resistance
Watches are classified by water resistance rating (I to V). Refer to the table below to ensure correct usage.
| Rating | Marking | Splash, Rain, Washing | Swimming, Snorkeling | Scuba Diving |
|---|---|---|---|---|
| I | (No Marking) | Yes | No | No |
| II | WATER RESISTANT | Yes | No | No |
| III | 50 M WATER RESISTANT | Yes | Yes | No |
| IV | 100 M WATER RESISTANT | Yes | Yes | Yes |
| V | 200 M WATER RESISTANT | Yes | Yes | Yes |
| V | 300 M WATER RESISTANT | Yes | Yes | Yes |
Notes:
- Rating I: Watches are not water resistant. Avoid all contact with moisture.
- Rating II (WR): Water resistant according to ISO 2281. Brief contact with water is acceptable.
- Rating III (5 Bar/50m): Suitable for showering and brief swimming.
- Rating IV (10 Bar/100m): Suitable for regular swimming and snorkeling.
- Rating V (20 Bar/200m): Suitable for scuba diving (excluding deep dives requiring helium-oxygen mixtures).
Prohibitions for all water resistance ratings:
- Do not press buttons underwater.
- Do not set the crown underwater.
- Do not operate the watch if wet (e.g., after swimming).
- If the watch is exposed to saltwater, rinse it thoroughly with fresh water and dry it.
- Do not wear watches with leather straps while swimming. Avoid prolonged contact of leather straps with water.
Watch Care
Never attempt to open the watch case or remove the back cover yourself.
The rubber gasket, which protects the watch from water and dust, should be replaced every 2-3 years. If moisture enters the watch, have it checked immediately by a dealer or CASIO service center.
General Precautions
- Avoid exposing the watch to extreme temperatures.
- While designed for normal use, avoid rough handling and dropping the watch.
- Do not fasten the watch strap too tightly. A finger should fit between your wrist and the strap.
- Clean the watch and strap with a dry, soft cloth, or a soft cloth dampened with a mild detergent solution. Never use volatile solvents like gasoline, thinners, or aerosol cleaners.
- Store the watch in a dry place when not in use.
- Avoid contact with gasoline, cleaning solvents, aerosol sprays, adhesives, paint, etc., as these can damage gaskets, the case, and the finish.
Special Strap and Case Notes
- Some models feature silk-screened designs on the strap. Clean these carefully to avoid damaging the graphics.
- For resin straps: A white powdery substance may appear. This is harmless and can be wiped off. Sweat or moisture, or storage in high humidity, can cause resin straps to deteriorate, crack, or break. Wipe resin straps with a soft cloth to remove dirt and water.
- For fluorescent cases and straps: Prolonged exposure to direct sunlight can cause the fluorescent color to fade. Prolonged contact with moisture can also cause fading. Wipe off any moisture promptly and avoid contact with other surfaces. Rubbing fluorescent surfaces against other materials may transfer the color.
Operating Modes Overview
The figure shows the watch in the Current Time Mode.
Pressing [Button C] cycles through modes in the following order: Current Time Mode ➡️ World Time Mode ➡️ Countdown Timer Mode ➡️ Stopwatch Mode ➡️ Alarm Mode ➡️ Analog Time Mode ➡️ Current Time Mode.
Press [Button B] to turn on the backlight in any mode.
Current Time Mode
Pressing [Button D] switches display formats: Current Time (Hour/Minute/Second/Day) ➡️ Month/Day.
Setting the Time and Date
- In Current Time Mode, press and hold [Button A]. The seconds display will flash.
- Press [Button C] to cycle through settings: Seconds ➡️ DST (Daylight Saving Time) ➡️ City Code ➡️ Hour ➡️ Minute ➡️ 12/24 Hour Format ➡️ Year ➡️ Month ➡️ Day ➡️ Seconds.
- To adjust seconds: Press [Button D] to reset to 00. If the seconds are 30-59 when [Button D] is pressed, the minutes count increments by 1. If seconds are 00-29, minutes do not change.
- To adjust other values (minutes, hours, etc.), use [Button B] and [Button D].
- Press [Button D] to switch between 12-hour (P indicates PM) and 24-hour formats.
- Press [Button B] and [Button D] to select a city code.
- Press [Button D] to turn DST (Daylight Saving Time) ON or OFF.
- Holding a button allows faster adjustment.
- The day of the week is set automatically based on the date.
- The date can be set from January 1, 2000, to December 31, 2039.
- Press [Button A] to exit setting mode.
Backlight
Pressing [Button B] in any mode turns on the backlight. The backlight also activates automatically with audible signals. The EL backlight's brightness may decrease over time. An audible beep during illumination is normal and due to element vibration, not a malfunction. Backlight may be difficult to see in direct sunlight. Frequent use reduces battery life.
Analog Time Mode
Analog time is synchronized with the digital time. If it becomes unsynchronized:
- In Analog Time Mode, press and hold [Button A].
- Use [Button D] to adjust the time. Each press of [Button D] advances the time by 20 seconds.
- Pressing [Button B] while holding [Button D] allows for faster adjustment. Press any button to stop.
- Press [Button A] to exit setting mode.
World Time Mode
View the local time in any of 27 cities (29 time zones).
Viewing Time in Another Time Zone
In World Time Mode, press [Button D] to select a city. Press and hold [Button A] to turn DST ON/OFF for the selected city (DST indicator appears on the display).
| City Code | City | Difference from GMT | Other Major Cities in the Same Time Zone |
|---|---|---|---|
| HNL | Honolulu | -11.0 | Pago Pago |
| ANC | Anchorage | -10.00 | |
| LAX | Los Angeles | -09.00 | San Francisco, Las Vegas, Vancouver, Seattle, Dawson City |
| DEN | Denver | -08.00 | El Paso, Edmonton |
| CHI | Chicago | -07.00 | Houston, Dallas, New Orleans, Mexico City, Winnipeg |
| NYC | New York | -06.00 | Montreal, Detroit, Miami, Boston, Panama City, Havana, Lima, Bogota |
| CCS | Caracas | -05.00 | Santiago |
| RIO | Rio de Janeiro | -03.00 | Sao Paulo, Buenos Aires, Brasilia, Montevideo |
| -02.00 | Praia | ||
| GMT | +00.0 | Dublin, Lisbon, Casablanca, Dakar, Abidjan | |
| LON | London | +00.0 | |
| PAR | Paris | +01.00 | Milan, Rome, Amsterdam, Algiers |
| CAI | Cairo | +02.00 | |
| JRS | Jerusalem | +02.00 | |
| JED | Jeddah | +03.00 | Kuwait, Riyadh, Aden, Addis Ababa, Nairobi, Moscow, Shiraz |
| THR | Tehran | +03.05 | |
| DXB | Dubai | +04.00 | Abu Dhabi, Muscat |
| KBL | Kabul | +04.05 | |
| KHI | Karachi | +05.00 | Male |
| DEL | Delhi | +05.50 | Mumbai, Kolkata |
| DAC | Dhaka | +06.00 | Colombo |
| RGN | Yangon | +06.50 | Jakarta, Hanoi, Vientiane |
| BKK | Bangkok | +07.00 | Singapore, Kuala Lumpur, Beijing, Manila, Perth, Ulan Bator |
| HKG | Hong Kong | +08.00 | Seoul, Pyongyang |
| TYO | Tokyo | +09.00 | Darwin |
| ADL | Adelaide | +09.05 | |
| SYD | Sydney | +10.00 | Melbourne, Guam, Rabual |
| NOU | Noumea | +11.00 | Vila |
| WLG | Wellington | +12.00 | Nadi, Nauru, Christchurch |
Countdown Timer Mode
The countdown timer can be set from 1 to 60 minutes. A long beep sounds when the timer reaches zero. The last 10 seconds emit short beeps every second. With auto-repeat, the timer restarts automatically after reaching zero, up to 8 times.
An audible signal can also be set for the countdown process. Four short beeps sound at the start of every fifth minute and 30 seconds before the end. Then, beeps sound every second for the last 10 seconds.
If the start time is 6 minutes or more, beeps sound every second for the last 10 seconds down to the 5-minute mark. At the 5-minute mark, four short beeps sound.
Setting the Timer
- In Timer Mode, with the start time displayed, press and hold [Button A]. The start time display will flash.
- Press [Button C] to cycle through settings: Start Time ➡️ Auto-Repeat ➡️ Sound Signal.
- Use [Button D] and [Button B] to set the start time. The range is 1 to 60 minutes, in 1-minute increments.
- Press [Button C] to cycle through settings: Hour ➡️ Minute ➡️ Hour.
- Use [Button D] to increase and [Button B] to decrease values. Holding a button speeds up adjustment.
- The 12/24 hour format matches the current time setting. Be mindful of AM/PM in 12-hour format.
- Press [Button A] to return to the Sound Signal setting.
- Press [Button D] to turn the sound signal ON or OFF.
- Press [Button D] to turn auto-repeat ON or OFF.
- Press [Button A] to complete settings.
Using the Timer
Press [Button D] in Timer Mode to start the countdown. Press [Button D] again to stop. Press [Button D] to resume. Press [Button A] after stopping to reset to the start time.
Stopwatch Mode
The stopwatch measures elapsed time, split times, and dual finishes. The maximum elapsed time is 59 minutes and 59.99 seconds.
- Measuring Elapsed Time: [Button D] (Start) ➡️ [Button D] (Stop) ➡️ [Button D] (Restart) ➡️ [Button D] (Stop) ➡️ [Button A] (Reset)
- Measuring Split Times: [Button D] (Start) ➡️ [Button A] (Split) ➡️ [Button A] (Resume) ➡️ [Button D] (Stop) ➡️ [Button A] (Reset)
- Dual Finish: [Button D] (Start) ➡️ [Button A] (Split. First finisher's time displayed) ➡️ [Button D] (Second finisher's time) ➡️ [Button A] (Cancel Split. Second finisher's time displayed) ➡️ [Button A] (Reset)
Alarm Mode
Set various daily alarms. The alarm sounds for 20 seconds at the set time. If the hourly chime is ON, a short beep sounds at the start of each hour. If snooze is ON, the alarm will repeat every 5 minutes.
Setting an Alarm
- In Alarm Mode, press [Button D] to select the alarm type: AL1, AL2, AL3, AL4, SNZ (Snooze), SIG (Hourly Chime).
- After selecting the alarm type, press and hold [Button A]. The hour digits will flash, indicating they are selected for setting. The alarm automatically turns ON when you start setting it.
- Press [Button C] to cycle through settings: Hour ➡️ Minute ➡️ Hour.
- Use [Button D] to increase and [Button B] to decrease values. Holding a button speeds up adjustment.
- The 12/24 hour format matches the current time setting. Be mindful of AM/PM in 12-hour format.
- Press [Button A] to return to the Sound Signal setting.
Testing the Alarm
In Alarm Mode, press [Button D] to test the alarm sound.
Turning Alarm/Hourly Chime ON/OFF
- In Alarm Mode, press [Button D] to select the alarm type.
- After selecting the alarm type, press [Button A] to turn the selected alarm ON or OFF. The "AL" indicator appears for any selected alarm. "SNZ" appears for snooze. "SIG" appears for hourly chime.
Technical Specifications
- Accuracy: ±15 seconds per month at normal temperature.
- Timekeeping: Hour, minute, second, AM/PM, year, month, day, day of the week.
- Calendar System: Auto calendar (2000-2039).
- Other: 12/24 hour format, DST (Daylight Saving Time).
- Power Source: Battery (model CTL1616).
Product Information
- Product Name: Electronic / Electro-mechanical Quartz Wristwatch (Men's/Women's)
- Brand: CASIO
- Manufacturer: CASIO COMPUTER Co., Ltd. (1-6-2, Hon-machi 1-chome, Shibuya-ku, Tokyo 151-8543, Japan)
- Importer: ООО «Касио», 127015, Россия, Москва, ул. Бутырская, д. 77
- Warranty Period: 1 year
- Authorized Service Organization: As specified in the warranty certificate.
