The screen on the inside of my gpsmap 76 got wet. how can i find out if the unit is still powering up so that i can download my waypoint to my p.c.

From the saved data when you backed it up on the computer. Use Garmin Express to transfer.

How to Backup User Data from GPS 72/76 or GPSMAP 76/76S

https://support.garmin.com > en-CA
It is recommended to occasionally back up the user data on your GPS 72/76 or GPSMAP 76/76S. User data includes waypoints, routes, tracks, and geocaches.

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  Transfer User Data From MapSource to a GPS 72/72H/76 or ...

  https://support.garmin.com > en-CA
  To transfer user data, such as waypoints, routes, and tracks from the MapSource program to these devices, some additional equipment will be required.
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  Manually Creating Waypoints on GPS 72/76 or GPSMAP 60 ...

  https://support.garmin.com > en-CA
  Press and hold Enter · Wait for the New Waypoint screen · Release Enter · Highlight the Coordinates field · Press Enter · Adjust the coordinates as desired with the ...
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  Backing Up Userdata (Waypoints, Routes, and Tracks) From a ...

  https://support.garmin.com > en-CA
  Before updating device software, it is recommended that you back up user data like waypoints, routes, and tracks. This should be done at regular intervals ...

To edit an existing waypoint:Or MOB
1. From the Home screen, select Information > User Data > Waypoints.
2. Select the waypoint you want to edit.
3. Select Edit Waypoint.
4. Select the waypoint attribute you want to change (Name, Symbol, Depth, Water Temp,
Comment, or Position).
To delete a waypoint or an MOB:
1. From the Navigation chart, use the map pointer ( ) to highlight the waypoint or the MOB
on the Navigation chart.
OR
From the Home screen, select Information > User Data > Waypoints.
2. Select the waypoint or the MOB you want to delete.
3. Select Review > Delete (The Review button is only shown when more than one waypoint
is in the vicinity.)

Every waypoint in the track has date/time, altitude and position. Second and subsequent waypoints will enable calculation and display of leg length, time, speed and direction between each par of points. The track can be displayed in 3D; in Google Earth for example. As far as I know there is no way to change the interval.

Have you enabled the 'WAAS' option?
This improves accuracy greatly

With unit off, press and hold ENTER and PAGE while powering on to perform a master reset.

Doing a master reset will erase and data in the device and restore it to factory defaults. So if you have any waypoints/tracks/routes you may want to back them up first.

You may want to update your mapsoure software first and see if that helps the issue. If not reinstall the software.

oh and double check your micro SD card to make sure its not damaged and is inserted all the way in.

I have run into the same problem and it may be related to the WAAS (Wide Area Augmentation System) feature. Try disabling this feature (under MAIN MENU / Setup). I used this receiver overseas (Asia and Europe) last year for 35 days straight with no problems. During this time WAAS was disabled as none of these satellites are visible overseas. The problem occurred intermittently prior to the overseas trip, and has reoccurred after returning. I was running into the same problem this past weekend and noticed the screen blanking out (with the vertical line) shortly after differential corrections were applied to the GPS signals. I disabled the WAAS and let the receiver run for over an hour. The problem did not return. Hope this helps.

You can't turn the navigation back on with this method. You must once again highlight the waypoint you want to navigate to in your Fine>Waypoints screen and then press the "Go to" highlighted button on the screen.

You need to do an auto locate. This also corrects your time issues (wrong date and/or time will be corrected. To do an auto locate do the following.

1. Start with the unit turned off.
2. If you have a GPSMAP 76, GPSMAP 76C, or GPSMAP 76S, hold down the Page button. If you have a GPSMAP 76CSx or GPSMAP 76Cx, hold down the Zoom Out button.
3. While holding down the first button (Page or Zoom Out), press and hold the Power button.
4. Continue to hold the two buttons until the Satellite page displays. You can then then let go of the buttons.
5. Finally, let the unit sit outside with a clear view of the sky. Allow about 20-40 minutes for the unit to acquire satellites.

If your software is less than v4.00 then download this update:

GPSMAP 76 Ver. 4.00 as of Nov 29, 2006

If that doesn't work it may be necessary to do a master reset.

My problem exactly. Unit would start up, acquire satellites, then the screen would go blank with a single vertical line. Unit would not respond to buttons or even turn off. Unit works fine after I did the reset:

- w/unit OFF, press and hold QUIT+DOWN+MENU
- press and release the power button, release DOWN, keep holding QUIT+MENU for 5 seconds.
- unit prompts something like: "erase all data;" choose yes.
- you will lose waypoints, etc.

Go to the Garmin support area for details.

http://www.garmin.com/garmin/cms/site/us/support/searchsupport

Search for: "How do I reset my gpsmap 76"