Topic: No fish signals

[joe]

Hi,

I've posted this on another forum but didn't have any joy. Anyone here help?

I have my SI unit for 2 years now and I've been very happy with it's performance. Unfortunately, (like most anglers), I don't seem to get out half often enough, so it took me a while to notice that everything wasn't as it should be with my unit.

I initially noticed this after I upgraded the software to the revision level before the DI revision, (whichever one that is), but I put it down to just a scarcity of fish in a given water or just that the fish were holding up very close to the bottom. After a couple of trips though, I was getting suspicious, so just to check that it wasn't my settings, I spent about an hour on the water with an 8" soft plastic bait, dragging it backwards and forwards under the transducer at different speeds, depths and at different settings etc. The outcome of this test was that the unit seemed to be picking up the soft plastic on a very intermittent basis. It was about this time that the DI revision became available, so I downloaded that to my unit and tested it at home in simulator mode. Brilliant, back in action with lots of fish symbols and arches all over the screen, or so I thought! I had my first trip out with the new software last weekend and once again, I was hardly picking up any fish symbols or sonar arches, no matter what settings I used. My buddy was fishing in another boat and he was picking up fish on his Garmin in all the areas where we'd expect them to be at this time of the year, so now I'm convinced that there's something wrong with my unit.

If I was to guess exactly when this problem started I would say that it happened after the upgrade before the DI one, but I couldn't be certain. Anyone out there have any similar problem or could one of the guys from Humminbird offer any advice?

[Humminbird_Greg]

Joe,
I remember reading this same post on another board but do not remember which one or if I replied to it.  When you tested with the soft plastic bait did it have a jig head or lead ahead of it?  The unit could have been picking this up and not the actual soft plastic bait.

Is there any chance that you can test your unit on someone else’s boat to see if it performs as well as their Humminbird unit?  This does not have to be another 797 unit as most of our units use the same 200/83kHz conventional sonar.  It could be another Si unit or any of our DualBeam units.  Just be sure and connect only the power and transducer (no GPS Receiver).

[joe]

Hi Greg and thanks for the reply.

Unfortunately, there aren't many Humminbird SI users here in Ireland. Only one other from what I can see from the members list here, so there's not much chance of me being able to carry out the checks you've suggested with another unit.

Regarding the soft plastic jig, I tried different types, leaded and unleaded, (with the lead built into the body, e.g. bull dawgs etc.), all with the same result. I used to use this for checking my settings in the past and it always worked.

One thing has occured to me though. Would the ping speed/chart speed make a difference. I guy in a Bass Pro shop once told me to set it to the max at all times. In hind sight, would this possibly lead to shrinking my signals causing me to miss fish? Only guessing as I'm a rookie with sonar technology.

My gut is telling me that there's soomething wrong though, but I'm open to suggestioins.

[Humminbird_Greg]

Well that’s going to complicate things a bit Joe.  Anyone else you know locally with a Humminbird unit at all?  This can be one of the more conventional 2D sonar units.  You said that you are not seeing fish in either the Si or the 2D sonar, so let’s start with the 2D sonar and test your 797c2 Si unit on someone else’s 2D transducer.  Just connect to power cable and transducer up for this testing.

The software before the software that gave your unit the down imaging feature is the 4.180 software.  If you would like to load this older software and try it with that you can do so.  Check the software download section of the web site for this version.  You can always go back to the present version if needed.

Increasing the Chart Speed would have the effect of stretching any sonar signal out.  So the fish would look more like long (horizontal) lines on the display.

Try setting the SwichFire menu to the “Max Mode” to help show more fish on the display of your unit.

[joe]

Hi Greg,

I don't know any Humminbird users over here. Ironically, I last unit I had was a Humminbird and I sold that on to a friend of mine when I bought the 797, but he's somehow managed to mislay it! So I'm stuck with fault finding on my own.

When I enable "SwitchFire" mode my screen just fills up with clutter and to be honest since I've downloaded that function when it was called TVG I've found the same so I just never bothered using it. TO me it seems that that's where my troubles began.

Strange thing is, when I use the unit in demo mode, it works like a dream. I can adjust the settings to show perfect sonar arches or fish signals, whichever I choose. I can turn on SwitchFire and play around with that and it all works fine. It's on the water that's the problem.

I think I'll just reload the original version of the software and see if I can get back to basics. If that works out, I'll reload the latest software to see if the problem reoccurs. If I can't get the old version to work, well that pretty much leaves it as a transducer fault I'm sure?

What's the warranty period on transducers? Or what's my chances of getting a discount on a HD transducer if it comes to that??

[joe]

Just thought of another question Greg; is it even possible for the transducer to be the problem? After all, I'm picking up the bottom structure, i.e. rocks, shelves etc, just little ir no fish signals.

[Humminbird_Greg]

Joe,
I don’t know what the different International warranties are.  You would need to get this information through the dealer you bought the unit from.  You would need to talk to them as well about any possible discount on an HDSi transducer.

The problem could be the transducer.  That is why I suggested testing it on someone else’s boat.