Thanks Larry for the very informative feedback but the problem goes further
than that and maybe I didn't explain myself clearly enough. If I'm watching
the screen scrolling by with fish or not, all of a sudden the display ends
with a dark vertical black line and just a clear empty screen following it.
I can stay clear for a 1/4" width or a 1" width up to a full screen width
before I see another dark vertical line followed by the normal display of
the bottom and fish if there are any. It has gotten so bad that I'm now
getting a 1/2" of display, a vertical line followed by a 1/2" of blank
screen, a vertical line, then another 1/2" of display, then a vertical line
followed by a 1/2" of blank screen, a vertical line, and this may go on
repeatedly forever. Sometimes if I shut it off and wait awhile it may work
okay for a minute or so and then it starts to act up again.

Jerry



"Larry" wrote in message
...
"Jerry" wrote in news:VaidnbSbjb-
:

Could I possibly just have a bad transducer at this point or is the
fishfinder kaput?



The trouble with automatic ranging, high powered fishfinders at very high
gains is they hear THEMSELVES, way too much. The ping bounces off the
bottom and reflects back. The sonar hears the first ping, great!
However, the ping also bounces off the hull, back to the bottom, and the
sonar hears the reflection...second ping. Sometimes they'll even hear a
third or fourth if the bottom is close, like 20' or less.....giving it
multiple targets to screw up the computer setting the power and
ranging.....

Try setting the ranging to manual and 3 times too deep from the real
bottom and have a look at the screen. You'll see more than one bottom
line on the chart, maybe even more than one fish, too! Large fish, like
a bottlenosed dolphin looking for lunch, will also confuse it if they
swim under the boat. They're so big they LOOK like the bottom to the
poor computer, not a fish....

The other problem with fishing spots is those other idiots also pinging
the bottom on your same frequency at your same repetition rate.
Obviously, they are less of a fisherman than you. So, they follow you to
find the fishing spots, pinging madly trying to see what you see. Their
pings sound just like your pings! What's a computer to do? It just goes
crazy switching ranges, ping power output, rep rates that follow the
ranges and pulse widths.

The tech on the bench, of course, doesn't have this problem....(c;

How hard is the bottom you fish over. Rocks make the multiple
reflections worse because they send back such a strong reflection the
boat reflection is strong and the pings bounce all over the place.

Engine noise and bubbles under the hull also make it go crazy from all
the noise and intermittent bottom sensing.

Take control of the GAIN, the receiver sensitivity, manually and lower it
until you can just see the bottom reliably....ONCE. The problem will
probably go away. Your receiver is working too GOOD!