The sun is high in the sky and the fish finder screen is not showing the arches and structure of the lake or river bed that it should be showing. Instead of showing the arches and structure of the lake or river bed, the screen could be displaying a blank blue field or an erratic mess of lines. Few things will end a fishing trip as quickly as encountering these types of problems with the fish finder screen.
Even the best of fish finder units sometimes experience problems that leave anglers wondering if the fish have all of a sudden vanished from the area that they were previously spotted in. The problems with fish finder screens are generally not mysterious in there causes. Most problems have common causes that an informed fish finder unit owner can easily diagnose.
The list that follows will explain the type of problems that is most likely to be encountered by those who use fish finder units, the reasons for the occurrences of those problems, and the methods for correcting each of those problems. One of the first issues with fish finder units is the problems with the power supply of the unit. These types of problems can be sneaky and can occur with a frequency that anglers may not expect.
Common Problems With Fish Finder Units
1. Power Supply Issues
For example, an owner may start the fishing boat and the screen of the fish finder unit may turn on, but the unit may continually reboot itself or the backlight of the screen may flicker. In each of these instances, the cause is likely a loose fuse or a corroded connection at the boat’s battery. An owner can fix each of these issues by inspecting each of the connections between the battery and the fuse holder and cleaning them with a wire brush and dielectric grease.
For those who experience these types of power supply issues with their fish finder units, installing a dedicated fused circuit that runs from the starting battery of the boat can fix the problem with the unit permanently. Although such a problem may seem small, it is important to fix these types of issues because the angler may be miles away from the boat ramp. The second most common problem with fish finder units is issues with the mounting of the transducer.
2. Transducer Mounting Problems
The mounting of the transducer can ruin the installation of the transducer even if the installation of the transducer itself was otherwise perfect. For example, if the transducer is not mounted in a way that it is perfectly parallel to the waterline of the fishing boat while the boat is traveling at speed, or if the transducer is mounted in an area within the water where the water is known to be turbulent (such as directly behind a strake on the boat), the signal from the transducer can scatter. This scattering of the signal from the transducer can cause the fish finder unit to not display the lake or river bed in the screen.
A fishing boat and fish finder unit can be installed with the transducer incorrectly mounted by taking a test run with the boat’s motor in the water and with the fish finder unit powered on. The angler can adjust the angle of the transducer during these test runs to find the perfect angle for viewing the lake or river bed. Anglers who fish at high speeds can install a second fish finder transducer on the back of the fishing boat, and they can mount the primary transducer under the hull of the fishing boat.
This extra effort can save the angler time during the first fishing run at speed while the boat is on the water. A third problem that can frustrate those who own fish finder units is the incorrect selection of the frequency that is to be used by the unit. Most fish finder units come with the default setting of 200 kHz.
3. Incorrect Frequency Selection
This setting is good for viewing the lake or river bed in areas that are only tens of feet deep. However, if the angler is fishing in areas that are beyond 20 feet in depth, the narrow beam of the 200 kHz signal may miss some of the fish that are suspended from the sides of the lake or river bed. In these instances, changing the frequency to 83 kHz or to the new “chirp” ranges that are available on most fish finder units will reveal marks on the lake or river bed that the angler did not know were there.
However, there will be slightly less resolution of the area that is directly beneath the fishing boat. Anglers who understand how the fish finder units work can learn how to change the frequency in which they are fishing. For example, one frequency can be programmed into the unit for scouting areas in the lake or river bed, and another frequency can be programmed to viewing areas with schools of fish once that boat is being anchored at a location.
Another problem with fish finder units is with the data that is displayed on the screen due to interference with other electronics on the boat. For example, the screen may display a school of fish that are actualy not visible to the fish finder unit’s screen, but which are likely being caused by the trolling motor for the boat, the electronics of other boats in the area, or the VHF radio on the boat. The angler can adjust the gain of the screen to reduce the display of this interference, but reducing the gain may also make it impossible to view the fish that are of interest to the angler.
4. Electronic Interference
In these situations, the angler can turn off each of the electronics on the boat one at a time until the problem with the screen is resolved. The cause of the interference can then be rerouted around the fish finder unit or it can be eliminated with the addition of a ferrite choke. Each of these electronics can also be placed on separate power buses from the fish finder unit to avoid the interference between the two electronic devices.
A fourth problem for those who use fish finder units are the bugs that are created within the software that is installed on each of the units. The fish finder unit may work well while the angler was fishing during the last fishing season, but during the spring fishing season the unit may freeze on the splash screen after being turned on, or it may refuse to read the GPS coordinates of the area where the angler intends to fish. The manufacturers of the fish finder units sometimes releases software updates that contain fixes for issues that occurred with the compatibility of the fish finder units with new mapping cards, or updates that resolve signal processing errors of the unit.
5. Software Bugs
Before assuming that the unit is broken, the owner can check for software updates that are made available by the manufacturer of the unit. The update process for the software takes only ten minutes to complete, and the update resolves the problems of more fish finder units than the anglers are aware of. Before performing the software update, the angler is required to back up any waypoints that are stored in the unit.
These waypoints contain the coordinates of the “fishing holes” that were marked during the previous fishing seasons. Fifth problems include temperature and speed sensors that may send misleading readings to the angler. For example, the temperature sensor may read the temperature of the water to be ten degrees warmer than the actual temperature of the water.
6. Temperature and Speed Sensor Errors
Anglers may waste hours fishing in the incorrect depth of the lake or river. Additionally, the speed sensors may misread the speed at which the boat is traveling over the water. For instance, if the boat’s paddlewheel is incorrectly set or damaged, the speed at which the lure is traveling may be incorrect by a few miles per hour.
These incorrect speeds can waste both the gas that was used to start the fishing boat, as well as the angler’s time when fishing with the lure that was programmed to travel at those speeds. Each of these temperature and speed sensors can be wiped down with a soft cloth to restore its sensors to full accuracy. For boats that remain in the water all year long, installing a transom-mounted sensor for such measurements allows the angler to clean the sensor without moving the boat out of the water.
Sixth problems with fish finder units include mapping and waypoint errors. In extreme situations, the screen may display an image of the angler’s boat located in the middle of an island. Additionally, the screen may refuse to display any contour lines of the area that was purchased with the mapping package that came with the unit.
7. Mapping and Waypoint Errors
These mapping problems are typically caused by using an out-of-date chart card for the area that is being displayed on the screen. The file on the chart card may become corrupted during the transfer of the file from the computer to the fish finder unit. Additionally, the software on the fish finder unit may be out-of-date relative to the mapping package that is installed on the unit.
These problems can be fixed by inspecting the chart card to ensure that it is inserted correctly into the unit, and ensuring that the unit has the most recent firmware installed. Finally, issues with the readability of the screen when it is exposed to direct sunlight can be frustrating for anglers. For example, the angler may purchase a fish finder unit that has a screen with a high brightness setting, but when the boat is exposed to the direct sunlight of the mid-day sun, the screen may appear washed-out.
8. Poor Screen Readability
Additionally, if the angler wears polarized sunglasses when fishing, the screen readability problem can be made worse. Instead of purchasing a high-end model of the fish finder unit, many of the units in the middle of the market range have features that allow them to display the information on the screen clearly in direct sunlight. For instance, the angler can adjust the brightness curve for the screen to compensate for the sunlight, or a color palette can be applied to the screen that is created for daylight visibility.
Some fishermen even purchase a visor for the screen or apply polarized film to the bezel of the screen. The best method for avoiding poor screen readability is to test the screen of the fish finder unit while on the water and in the same lighting that the angler will use when fishing. These types of problems may seem relatively minor when the angler is in the tackle shop browsing for purchases.
However, these problems can become major obstacles in the angler’s pursuit of the next big catch. By understanding the language of the fish finder unit, the angler can overcome each of these obstacles. The next time that the angler encounters any of the problems listed in this article, they should refer to the list before using the warranty period for the unit.
Most of the time, the fish are still located in the water. The angler merely needs to have the proper window to view the fish.