Symptom: No GPS at all (display reads 0 satellites tracked).
1. Check for 5V DC coming out of the antenna port on the side of the unit. If below 4.8v DC, receiver board has failed or not getting 12v DC to the unit.
2. If reading is above 4.8v DC, reattached antenna cable and check the other end of antenna cable.
-If the voltage is the same as the antenna port, try a different antenna.
-If the voltage is less than the antenna port’s, try a different cable.