Problem With Garmin Sonar

[live bait]

Hope we have some Electronics members here so here goes. I have a Garmin 1242 XSV chart plotter/sonar combo on the boat that has worked fine for three years & most of this spring. The last couple trips when set on sonar I'm not seeing fish marked on the screen. I see the bottom contours just fine, I see my water temp, & speed just no fish when I know I'm over fish & have been catching fish. The sonar fish alarm is set to small, medium, & large fish, not a sound. Last week over a pod of bunker, no marks, no chirps, catching blue fish the same no marks or sound. transducer is thru hull & clean, tried turning up the gain, same result, & that's the extent of my electronics knowledge.
John

 

[Roccus7]

The sonar fish alarm is set to small, medium, & large fish, not a sound. Last week over a pod of bunker, no marks, no chirps, catching blue fish the same no marks or sound. transducer is thru hull & clean, tried turning up the gain, same result, & that's the extent of my electronics knowledge.
John

John:
I may be old school, but being one who grew up with learning how to distinguish fish from marks on paper tape, I've never used, nor trusted the fish alarms, and those cute little fish they show on the screen. I've learned to tell what's going on by just looking at the screen.

To meet my definition of "Is it working?", I'd ask if the bunker schools showed up? If they do, and as you mention, there's a nice clear picture of the bottom and the structure, then you're good.

Didn't you post a screenshot last week with "FISH" marks above and below the nicely displayed school of bunker? I believe another one of our colleagues gave the same advice as I'm basically saying, "Forget the 'FISH' displays."

 

[live bait]

I don't think I have posted a screenshot in the past, must have been another member. In the past I would get a boomerang type mark on the screen representing a fish & the machine would make a chirp sound alerting to a fish. I now get a clear representation of the bottom structure, & a clear screen to the surface with no targets. When I was over the bunker school the screen between the bottom & the surface showed nothing. I'm in the process of making an appointment to have radar installed in the next week or so, at the same time I'll have "the guy" take a look at the sonar.
John

 

[Roccus7]

When I was over the bunker school the screen between the bottom & the surface showed nothing. I'm in the process of making an appointment to have radar installed in the next week or so, at the same time I'll have "the guy" take a look at the sonar.
John

Absolutely then. Strange that there's nothing showing between the surface and bottom. This is most confusing.

Just for giggles if you get out before seeing the tech, reduce the gain up all the way down and then increase it gradually when over a school of bunker. Maybe you're "shooting through them"?

 

[live bait]

Think I'm going to wait till Tuesday to fish, I want to get away from the moon a few days & give the tides a chance to slow down, I'll give the gain a try. Chances are, the electronic wiz that I am, I screwed something up.
John

 

[Roccus7]

Think I'm going to wait till Tuesday to fish, I want to get away from the moon a few days & give the tides a chance to slow down, I'll give the gain a try. Chances are, the electronic wiz that I am, I screwed something up.
John

Another thought. Could you have accidentally set the machine to only worry about a few feet above the bottom and to ignore the rest of the water column? Some of these machines are so sensitive to their touch screens and/or buttons it's a common problem. Many times I've looked at my machine and said, "HTF did that setting get changed"????

 

[BoatGuy]

Capt Jeff is also a charter boat captain. He is used to looking at screens and interpreting what things are. You may want to consider giving him a call to help. He helped me with my transducer.

 

[live bait]

Don’t think so BUT I could have done just about anything. John