I have a friend that has a 998c HD SI with a GPS receiver that has Precision GPS Receiver printed on the top of it. Last year he had a problem where he lost the map chart on the screen, after it was all working properly before he lost it, and the Navigation and Chart tabs in the menu were missing. He took the boat back to the dealer and they sent the unit to Humminbird to have it repaired. When they got it back and reinstalled on the boat, they called him to come pick up the boat because it was now working. When he got there, they told him that Humminbird told them that he had the unit set up wrong. I did not know that you would lose those two tabs on the menu when the GPS receiver would be disconnected. That is not mentioned in the user manual.
It has been working okay ever since. Last week he went out and when he got on the water, no map again, only sonar working. He fished, came home and called me. He brought the boat over the other night and I worked with him on it for about two hours. I have a 998c SI that is portable, so I took it out to the boat and used it to try different things to see what it could be. He still had firmware 6.490 that was on the unit when he bought the boat which was a dealer demo boat. I had 7.090 on my unit. With a Navionics map chip in the unit, there was nothing in the chart window. Thinking it might be bad, I had him pull it out and the preloaded maps in the unit did not show up. That had me thinking that the firmware might be bad. Reset defaults and Formated Nav Directories to make sure that was not a problem. Still the same. I updated my unit to 7.670 to make sure my unit would work with the new firmware. It did, so I updated his unit to 7.670 and when it booted back up after the update it was just the same. Sonar only with no Navigation or Chart options in the menu.
Took the cord connector holder off of the back of the unit and cleaned the plugs on the cords and unit. Put some dielectric grease in the plug sockets and tried it again to see if there was a connection problem. No, the same thing. Went into the Accessory Status and it showed that the GPS was connected. That through me for a loop to see that because I was now thinking that the GPS receiver was bad. I disconnected my GPS receiver form my unit and booted it up and the Accessory Status showed that my GPS was connected. It also shows that Radar and MNEA 2K Gateway is connected, which I do not have connected to my unit. I now do not have the Navigation or Chart tabs in the Menu either on my unit and it does not show any map on my unit with a Navionics chip in it or with the chip out to see the preloaded maps.
I told him to call Humminbird back and tell them everything that we did and have decided that the GPS receiver has to be bad because the first time he called them last week they said the unit is not setup correctly, to see what they say now.
He is going to call up a different dealer that he has been working with lately to see if they have a new GPS receiver in stock that they could try on his unit to see if it would work. I had no way I could hook my power cord or GPS receiver to his unit to see if my receiver would work on his unit.
On my unit now when I work on it in the house, the GPS Not Connected warning box does not flash on and off of the screen, when it IS connect but not receiving any satellite signal. When that box would be on the screen, anything I was doing at the time stopped and would have to wait until it went off the screen to continue working. Happy that they finally changed that after two years of this happening with this new firmware update.