Is my FF done?
 

How do I know that my Fish Finder is done. It worked a month or so ago and I can't get it back....nothing. Can I get new connectors from Garmin, I have a Garmin 240. Any other suggestions? I've tried the acid and dielectric grease.....don't know what else to do. Would love some help. Thanks.

Have you tried contacting Garmin? My Hummingbird was out of commission a while ago and I sent it in for repairs. $90 bucks and good as new with additional warranty on the parts they replaced.

You use a DMM to ring out the power lines on the connector or check the voltage at the connector with the battery hooked up. Do you have any crimped connections, those don't last long around saltwater.

I don't know what they would charge but sending it in for service might be the trick to have it refurbished.

Bring it by any of the OEX stores and we'll trouble shoot it before you send it back to Garmin (no charge). A lot of times it's just corrosion in the power cables and the head unit is just fine. Some new wire, fuse holder and battery connector would run you less than $20 if we find out that stuff needs to be replaced.