No responce I was running my GPS in the boat connected to battery power, when I noticed the screen had gone blank and did not respond to any button commands. I have since checked the battery voltage and plugged it into the mains power with still no response. Any clues what I should be checking or does it sound terminal?

Ur touch pad is gone bad get it replaced

replace the touchpad

Hold the power button until the GPS reboots itself then change your settings back to how you had them, you will need to connect to your computer to get back all your POI's.

Had this problem and switched power cord and has worked fine since.

mcdevito75 here, Sounds right, the screen has gone. Contact Garmin about repairs, usually chaeper than a replacement.

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.

With the charts page up, start by hitting the find ship softkey at the bottom of the screen.If that find the boat on the chart all is good.If not you need to check you have a GPS fix. Go to GPS screen and see you are seeing satalites.
If all is good when you hit find ship and the boat disappears again from chart while underway you will need to go into the chart setup menu and see if the screen amplifier is turned off. If off turn on.This is first place to start. Hope that helps

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"

had same problem. the cause was corrosion in the boat wiring. the power wire was corroded 95%thru. there was enough voltage to start the unit but when the sounder kicks in the voltage dropped below minimum and the unit shut off. took a LOOOONG time to find.