I have a Eagle Fishmark 480. Last year it worked fine. Now it takes a long time to find bottom depth when I first turn it on. When it does it will stick at 2.8 feet. It has the most problem with 5 to 10 foot depth when in auto range. It will read for a while and then go back to 2.8 and the depth bar will read 0-5 feet. If I switch to manual depth range of 0-10 I can see the bottom structure but the depth reading will remain at 2.8. I'm guessing it's the transducer since it sat out in 30 to 40 below weather last winter. Has anyone else had these problems? I have same problem. Changed transducers twice but problem starts again.

Question edited for clarity.
Question moved from Eagle Televisions.

Phone and ask them if you can send it in. Very often your local marine electronics shop will have a preferred technician.

https://www.manualslib.com/manual/41681/Eagle-Fishmark-320.html?page=90

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Think of where the transducer is fitted on your boat . As turbulence is the only problem you need to worry about. It needs too be on the transom but in between the lower 2 chines

Hello! Do you have the PDF users guide for your unit? I'm looking at a copy in the troubleshooting section...I don't want to cover information you have already looked at or tried...Since I do not know if you have that manual I'll give you a few items to check...

Measure the battery at the units power connector...Must be at least 11 volts DC...In portable mode it uses 8 D cell batteries= 12 volts
Make certain the Transducer is securely connected...
Did you use the in-line fuse supplied with the unit?...
Try the Manual Depth Range...First turn off Auto Depth Range...From the sonar Page Hit MENU...Down-arrow to Auto Depth Range...Hit ENT...Hit Up-Arrow to Depth Range...Hit ENT..
And the Depth Scale Range appears...Up-Arrow or Down-Arrow to select a different depth range...Hit Exit...The minimum depth the unit can read is 5 feet...

If you do not have the PDF guide, here is the link...

http://www.eaglenav.com/upload/Eagle/Documents/Manuals/seafinder320df_0143-661_101602.pdf


Let me know how you make out....Guru....Saailer

I’m happy to help further over the phone at https://www.6ya.com/expert/david_6df67de3b14de867

Try adjusting ur puck,and go into menu look for a shallow,fresh water setting.less than a 100ft put in shallow all other depths in fresh

try hitting the on and off button it should fix it that is your lite skle and britness

This is the contact that I found on the net "Call Luke Morris, Lowrance, 918-438-8710, this guy works for them. Mondays is a bad time, he is hard to get ahold of, keep trying.", and with my research and my experience I suspect a bad power supply... If you have electronic skills, you could open it and check for swollen capacitors, specially on the power circuit board and replace them... (it's worth a try)

Good luck!

It seems most likely that your manual range has accidentally been set for 50' or less. Go into the menu and set to auto range. Here are the exact keystrokes as shown on PAGE 51 of your manual:
MENU> scroll down to DEPTH RANGE> ENTER> Exit

If this doesn't work, try doing a ful reset, as shown on PAGE 64 of your manual:
MANU> MENU> scroll down to RESET OPTIONS> <- to YES> ENTER

The Fishmark 320 is an excellent unit, and it works great in full-auto mode if you have the transducer mounted properly. Let us know if this doesn't fix your problem.

Try this.

http://www.eaglenav.com/upload/Eagle/Documents/Manuals/seafinder320df_0143-661_101602.pdf.

This problem is most likely linked with your transducer.

1. Check your transducer cable and make sure the plug terminals are clean, as well as the plug on the back of the unit.
2. Make sure the transducer cable is plugged in correctly and securely.
3. Make sure the transducer is in the water and mounted according to the directions, parallel to the bottom of the boat
4. Turn the unit on while the boat is in the water, but with the engine OFF.

IF it works when the engine is off, but vanishes when the engine is on, you may be having electrical interference.

IF it works when the engine is running, but vanishes when the boat is moving, it is a turbulence problem. Move the transducer.

IF it does not work at all, try borrowing a new or a "known good" transducer and seeing if it works then. If so, replace the transducer.

Let us know if these work or now.