GD-1920C not reading C-MAP Card


New member
I bought my boat about 10 years ago and it came with a GD-1920C plotter (series 4326-XXXX) with a C-MAP NT MAX SD Card installed. It has always worked flawlessly, and despite the fact that it is 15-20 year old technology, I just love it.
Then this summer I noticed the tide charts were out of sinc. I discovered the date in the plotter was thinking it was the spring of 2003! There was nothing I could do in the setup that would change the date. Turns out this is problem is due to the GPS antenna being out of date and not the plotter, from what I have gathered while reading different posts on this forum.
Problem is that I first looked on the FurunoUSA support site and saw that there was a driver update available (NavNet VX2 10.4 inch CCFL Navionics Software version 4.01), so I downloaded it along with the instructions, loaded the files onto a new SD Card, and followed the directions for loading the updates onto my unit.
The first hint that something was wrong is that the unit did not respond the way it should have as described in the instructions. The unit should have started beeping after the update was complete (per the instructions) at which point I was supposed to remove the SD-card and the unit would power itself down.
Instead, the unit (eventually - it took about 5 minutes) booted up like it always does. Since I had removed the C-MAP card from the SD card slot, the plotter screen showed a white background (no map), but correctly showed my GPS position and retained my "bread crumb" trail back to the dock from my last time out on the water.
I shut it down, removed the boot card and reinserted my C-MAP card, and turned on the unit. While booting up it indicated the same program version as before the update: 195002401.07.04.
However, the unit failed to read my C-MAP card and load the map data. Same blank white map screen. I have turned it off and on several times and no difference. I have removed and reinserted the C-MAP card several times to no affect. I now have a unit that will not read my map card.

What did I do wrong, and what can I do to fix this? Without the maps the unit is not much good to me. I just want my maps back!
You didn't do anything wrong. You just have extremely old 1.07 software that the current software won't update (because it is too old). For the software on our website to work, it needs a minimum of 1.08 software which you don't have. To update this unit, you will need to contact tech support for special software (what we call conversion software) that can force the programming to the newest. That is great and will help the machine run faster and better but it won't fix your core problem with the tides. To fix that you would need to replaced the older GP320B gps antenna that has rolled over. One would replace the sensor with the newer GP330B/0183 unit so that your time and date will be correct. With correct time and date, your tides then should also be correct.