Garmin gpsmap 76

[geonelson]

downloaded NE topos (3) to microSD card. Verified that correct amount of data was present but when inserted in GPS and went to "Map; information" no maps were found except marine map in internal storage

[Boyd]

You will need to tell us a lot more if you want help. Exactly what did you do when you "downloaded" the maps to the SD card? You cannot directly install maps from this site on an SD card. You must first install each map on your computer, then use either Basecamp or Mapsource to select a portion of eachmap and send it to an SD card.

The process is explained in these two tutorials

https://www.gpsfiledepot.com/tutorials/how-to-open-maps-in-garmin-basecamp/
https://www.gpsfiledepot.com/tutorials/how-to-load-maps-on-my-garmin-gps-unit/

Did you go through all these steps? If so, what kind of SD card did you use and how is it formatted. You must use FAT32 formatting or the card won't work in the GPS. That would be the default "out of the box" formatting on most cards 32gb and smaller.

[geonelson]

Followed tutorial precisely. Downloaded maps (3) to BaseCamp. Then plugged in 8GB micro SD inSD adaptor (after it had been formatted). Picked all of the topos (600+ MB) and used Mapinstall to install maps. They are on the micro card as an IMG file. Have a prior 128MB Garmin micr card with BlueCharts. That shows up fine on the GPS. New micro card does not show up.

[Boyd]

Is the card formatted FAT32? Does it have a folder named Garmin? What files are inside the Garmin folder?

[geonelson]

It is formatted FAT32. It has a garmin folder which has a 600 + KB IMG file labelled gmapsupp.

[Boyd]

That all sounds right. I would try using Mapsource instead of Basecamp/MapInstall. That is the software originally provided for the GPSMap76, Basecamp was released later. You can download here: http://www8.garmin.com/support/download_details.jsp?id=209

Mapsource should see the same maps that you have already installed in Basecamp. For starters, just send one map and see if that works. If so, then you can send them all. Here is the Mapsource tutorial: https://www.gpsfiledepot.com/tutorials/how-to-load-maps-on-my-garmin-gps-unit/#mapsource

Now there is one other possibility for what could be happening. These older GPS units have a rather restrictive "segment limit". Segments are the smaller tiles that make up the entire map. Your GPS can only access about 1000 segments. There is no standard size for a segment, it's up to the mapmaker.

In one of your posts you said the file was 600MB, but in the other post you indicated it was 600KB. A 600MB file might contain more segments than your GPS can handle. When you exceed the limit, unpredictable things can happen. However, I would expect that at least some of the map would work.

Anyway, Mapsource will tell you how many segments are in the map you're sending to the GPS (in the left pane of the window). I'm not sure if the current version of Basecamp/MapInstall shows this info.

[geonelson]

I very much appreciate you continued efforts. To date, I did use MapSource as you suggested to load NEtopo part 1 onto the micro SD. Could not see it on the GPS. But it was 628MB. The Blue Chart preloaded MicroSD which I can see is only 128MB. Reformatted the micro card and then used MapSource to load a toal of 3.1MB maps. Still cant see. Frustrating.

[geonelson]

One other thought: We know the GPS and its micro card reader are working properly as it reads the Blue Chart chip when inserted. We also know the maps were loaded properly onto a new card which was properly formatted. Could there be a problem with the new card? It is a Monster 8GB microsdHC w SD adaptor. Should I try a different card?

[Boyd]

Are you using the newest firmware on your 76? I have a 60csx which is identical except the 76 floats. No problems loading maps on it. Older firmware may not work with SDHC cards, but I think the newest firmware does. You can use Webupdater to  check and install new firmware if needed.

http://www8.garmin.com/products/webupdater/howtoinstall.jsp

Otherwise, try a 2gb microSD card, if you can find one (don't think anyone sells them anymore).

[geonelson]

Hooray!! The update did the trick! I can now see the topos. Thank you very much!!

[Boyd]

Great! that was tricky one, don't think we've seen that issue here before. Enjoy the new maps.