Topic: Intermittent Port Image Problem

[Doc Stressor]

Before I contact Humminbird support, I'm asking if forum members have experienced similar problems.

My 997 always had intermittent problems displaying the port side image display since it was new. I used to think that the problem had to do with weeds accumulating on the transducer, since backing the boat up would often solve the problem. But lately the problem has gotten much worse and I can only rarely get a port side image. I've eliminated weeds as the cause of the problem.

Here is an image with both sides working:



Here is what I usually see now:



The problem is still intermittent and you can see partial recovery of the port image in the following 2 images that were taken in sequence:





I am beginning to suspect an internal wiring issue in the transducer since hitting a wave or backing the boat can sometimes restore the image. Moving or reconnecting the cable at the head unit has no effect.

Has anyone had a similar problem or have any ideas as to what is going on?

[Humminbird_Greg]

Doc Stressor,
It looks more to me like the transducer is getting tilted somehow.  Are you in a light or aluminum boat that tilts easily?  If you look at the second image you posted: the far left portion of the left Si sonar looks like it has been influenced by waves.  Next time out try loading one side of the boat versus the other to see if you can make this happen or not.

It would not hurt to try someone else’s Si unit on your boat using the same power cable and transducer.  It does not have to be another 997c Si unit for this test.

[Doc Stressor]

The transducer is mounted about 15" from the centerline of a heavy 22" deep V hull. It stays fully submerged unless I'm on plane. The mount doesn't tilt and the 2D tracks bottom fine while I'm on plane.

The images were all collected on flat calm water. The boat sits level at low speed.

I haven't been able to find anyone local with a similar unit. I will have to keep trying to find somebody.

BTW, which models use the same transducer as the 997?

[Humminbird_Greg]

“The images were all collected on flat calm water. The boat sits level at low speed.”
Well now I’m boggled…
Do you have anything that may intermittently hang down to the left of the HDSi transducer that could be blocking the sonar?  Maybe the motor?

The following models use the same HDSi transducer as the 997 unit: 898, 998, 1197, and 1198c Si.  The 981c, 987i, 797 and 798 units would work for testing purposes as well since they all use the same 455kHz Si sonar.  Just be sure to connect up only the power and transducer for the test though.

[BaitCaster]

That looks very similar to the problem I had when my motor was blocknig the left side image.

[Doc Stressor]

It's not the lower unit  blocking the beam. The problem comes and goes without changing the trim of the engine. I can also tilt the engine completely out of the water when the port image is gone and it does not come back.

The transducer is mounted lower than the trim tabs as well.

As I said, I originally thought that the transducer was collecting weeds. But now the port image is gone most of the time and weeds are not involved.

I found a local guy with a 797 si who will let me test my head unit on his boat. I'll post of the results after we get together.