why is the SAMYUNG NF700 gps on but no picture

why is the SAMYUNG NF700 gps on but no picture, Samyung NF700
The Samyung NF700 plot plotter / fishfinder combination is a precision built 7" GPS chart plotter and fishfinder with a high-performance receiver for Global Positioning System constellations of satellites, providing accurate location data with a number of navigation features. Some functions require optional units and sensors installed on your ship.
Wide 7” high resolution TFT LCD
Fast screen response due to high performance CPU
10 step adjustable LED backlight
Multiple languages ​​available including Dutch, English, Chinese, Russian etc.
Built-in 128MB internal memory and standard Samyung chart
DGPS (WAAS, MSAS, EGNOS)
Easy to use icon based menu operation
NMEA 0183 interface (AIS, NAVTEX, DSC etc.)
2 split screens (Charts, Data, Roads, etc.)
Easy to use with auto gain
Suitable for small fishing boats
Uses a single frequency (200 KHz) for detection of minnows and individuals
Navionics GOLD charts (SD)

[@Nurhayati-p1g2i]

Slmt siang bang. Sy punya gps samyung n430 mengalami konslet pd waktu pemasangan kabel accu. Agar lebih jelasnya bisa munta nomor WA nya bang.