Furuno 585 Water Depth and Viewing Issue



I would consider myself a beginner when it comes to detailed knowledge with this unit. I have owned it for a year. I am having problems with the unit when I get deeper than 1,500'. I would like to just see the top 400' or 500' but the unit goes "crazy" as I call it. The water depth changes sporatically with inacurate readings. At this point, I'm not wanting to see the bottom but rather bait balls or large pelagics. I have tried to manually set the water depth to 600' but this doesn't seem to resolve my issue. Any help is greatly appreciated.

If I understand you correctly your FCV-585 is in the Manual Range mode but randomly changing ranges? If that is the case you should be able to dupicate this at the dock. Turn the machine on and press the range button to make sure the machine is in the Manual setting. Then set the range for 600ft and press the enter button to confirm your selection. Check to make sure the range changes to 600ft, at this point you can disregard the digital readout. Leave the sounder on for a couple of hours to see what happens, it should remain on the 600ft scale. If it doesn't ,press the Range button to confirm that the MANUAL is highlighted. Let me know what you find.

Snips, I understand what you are telling me but I have more of a problem. Yes, the range stays on 600' but the actual screen does crazy things such as losing my image. The screen will go solid and quicky change to clutter, etc... This only happens once I get in a water depth over 1,500' in which the sounder goes haywire. It essentially shuts down and doesn't want to give a clear reading of anything. If it matters, I am running a thru hull Airmar 1KW. Thanks.
Do you have the FCV-585 set for Manual or Fishing gain? Please know if the bottom doesn't appear on the screen the digital readout displays dashes (----). Meaning if you are in a 1000ft of water and have the sounder scale set at 600ft you should see dashes. Also if you use the Fishing gain on the 585 it will use the bottom as a reference point and automatically adjusts the Gain and Cluttler settings.

Thanks Snips. I will check my gain settings the next time and hopefully that's my problem. I am pretty sure I am using a manual setting on my gain instead of a preset setting for "fishing" but I might be wrong. I may be better off doing a factory reset while Im out there to see what happens.