1) Please power on the sensor first, then power on the display. If you turn on the unit in wrong sequence, please restart the display again.
2) Please make sure the radio environment is in good condition. Too close to the WIFI, BLUETOOTH device, or noisy R/C controller may result in a very short RC communiction distance.

1) Please be sure the antennas are connected properly. And the connector pin of the antenna is in good condition.
2) Please keep the antenna on the boat at least 15cm high above the water, and the antenna on the display 1.5meters above the ground.
3) Please make sure the radio environment is in good condition. Too close to the WIFI, BLUETOOTH device, or noisy R/C controller may result in a very short RC communiction distance.

1) The position accuracy of GPS depends on the satellites signal. If the weather is cloudy or raining, the satellites signal may become poor.
2) If your boat (with GPS receiver mounted) is stationary, the position coordinate may be drifting. Then the error of GPS accuracy may reach 15 meters or even more.
However, if your boat is moving with speed 0.5m/s or more faster, the position accuracy will become good enough.
3) Please be sure the mounted antenna of GPS receiver is at least 30cm far from any other antenna, such as antennas for boat or fishfinder.
4) In some country or region, for national safety considering, the local government may take some measures to interface the GPS satellites. Thus the GPS coordinate offset may be different at different time.

1) The mounted GPS receiver (with compass built in) should be far away from such substance: magnets,iron, nickel, etc. 30cm distance is recommended.
2) The accuracy of the electronic compass normally is in +/-15 degree range. So, it is normal if you found there is small error of the compass.
3) The GPS data of boat direction is updated in 2HZ (twice per second). So, if the boat is turning around at fast speed, the compass display on screen may be delayed.
4) If you find the compass completely does not show the proper direction, please refer page 30 to calibrate the compass by manual operation.

1) The transducer should be far away from any air bubbles, such as the engine and propeller. We suggest installing the transducer at 1/3 position form the head of the boat.
2) Bubble is the primary source of interference for all sonar equipments. So, the mounted transducer should be some depth under water. The deeper the better. 15cm is recommanded.
3) If the depth is less than 15cm, waves of water surface can affect sonar image quality. Adjust the sensitivity to 4-6 may help.

1) For all sonar devices, there are two blind regions, even for the high frequency sonar like the TF640, the blind regions still exist:
- One blind region: 0.5 m below from water sufreace.
- Another blind retion: 0.3m above bottom.
If fish is in the blind region, it is hard to detect. So, to get an perfect sonar performance, we suggest using the device in water not shallower than 1.2m.
2) [Fish ID. Sens.] menu control the threshold of fish size display. If needed, please set the [Fish ID. Sens.] parameter to 3

1) Oil, dirt and fuel might cause a film to form on the transducer and reduce its effectiveness. Cleaning the surface of the transducer might help.
2) TF630/640 is a high frequency sonar working at 460hz, the depth capability is 100ft theoretically. However it depends on the bottom condition. The mud can result week echo. So it’s recommended to use the device in water not deeper than 20m.
3) If a deeper depth capability is need, pleas choose transducer of 115Khz.

1) If the speed of boat (with GPS receiver mounted on) is less than 0.6m/s, the GPS data of boat heading direction will be always wrong. And generally the boat is very slow when it is close to the desination. So, it is difficult for you to precisely operate the boat reaching to the destination only with GPS function.
2) With the compass, you can observe the precise heading direction of boat even it is very slow.