Modern fishfinders are like modern cars – if they aren’t working right, you probably need a computer to fix them. Gone are the days when you could pop open the unit, fiddle with the wirse, and hope for a good outcome. In fact, virtually all modern fishfinders are factory-sealed, and in many cases, opening the box voids the warranty. So, what are you supposed to do if yours goes on the blink in the middle of a fishing trip? There are a few steps you can take, to try and get that unit pinging again.
First off, try a factory reset. Unfortunately, there’s no simple way to explain how this is done because different manufacturers have different methods. Most fo the time, it means shutting the unit down, then pressing a button or two and holding them down as you power the unit back up. To be prepared for this, you should print out the instructions (you should be able to find these easily with a little Googling round) and stow them in a zipper-lock baggis, somewhere aboard your boat.
If the issue is a fading screen or a false-start and then an abrupt shut-down, try turning off all of the boat’s systems and see if the unit starts acting properly. Often these are symptoms of low voltage, and your unit may simply not be getting enough juice. If this does work, before you continue fishing remember that you may well have a battery or alternator problem – not really a fishfinder problem – which could potentially leave you stranded on the water.
When your unit won’t even turn on, suspect a blown fuse or a faulty connection. Chase down all the fuses, check them, and double-check all of the wiring.
If the fishfinder can’t acquire bottom or loses it often, it’s almost certainly a transducer issue. First check the transducer mount, then the wires and connections. If you still can’t locate any problems, try to get a close up look at the transducer itself, even if this means pulling the boat. Peek at the molding seam, and look for any seperation or gaps. Sometimes the transducer will pull apart (usually due to impact or old age) and water gets inside, which glitches out the system.
If none of these fixes works, you’ll probably have to ship your unit back to the manufacturer. But before you print out that shipping label and send your unit on the road, give these quick-fixes a shot. At least half the time, one or another will work – saving you time and money.