How do I determine if i have a bad unit or the transducer is bad?

Take note if when the vertical lines appear on the screen if the depth numbers begin to flash. If this is the case then the transducer has lost bottom contact and the unit is trying to reacquire bottom contact. If the transducer is parallel to the bottom of the lake while your boat is not moving then, the next time you have it on the trailer, turn your unit on and go listen and or feel the transducer to see if you can hear and or feel the tick or sonar ping. If you can't your transducer may be faulty. If the loss of bottom contact occurs when you are moving it will happen at a certain speed. This is the result of air bubbles passing under the transducer and disrupting the sonar signal causing loss of bottom contact.

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

Hello Keneth,
Is The transducer In Side the Hull Or Mounted On The Transom?
If Inside Remove It And Re Fit It Using Epoxy Glue Ensuring No Air Pocket Between transducer And Hull.
If transom Mounted Replace Transducer.
Hope this Helps
Gordy

If the transducer is not correctly mounted this may happen due to air, etc. If the unit never gives a depth reading that looks like dashes
( - - ) then there is likely nothing wrong with it aside from the transducer placement.

The depth loosing bottom would certainly indicate that you may have growth fouling the transducer, however the sea temp 220 degrees indicates possibly a different problem. Start by being sure the transducer is squeaky clean and see what that does for you.

Your transducer needs to be adjusted so the return signal can be picked up. Some of these have to be super tuned to receive the signal. Also the transducer may be moving ever so slightly when the boat is traveling at speed. You may have some water turbulence interference all contibute to signal return.

A test bucket wont work, A 200 khz transducer will generally not work in anything less than 2' of water, due to surface clutter. If the transducer is working, you should hear it make a ticking sound.

When you got the 17000 foot reading was your range set to auto?

How is the transducer situated on the boat? Sometimes turbulence and bubbles from the hull can cause erroneous readings, including unrealistic depths, or no depth at all. Stop the boat and turn off the engin e and anything electrical to see if problem repeats itself. If it only crops up when the boat is moving then it is most likely the transducer location.

Depending on your transducer type, you may have a liquid filled type that simply needs refilling. If this is the case check for leaks and get it redone. If not it could be transducer placement or cavitation under the hull.