I was on the water spooning with my Lowrance X-16ci, one of those new fangled, sophisticated, and computer controlled depth finders. I had cruised an area and marked fish on my console Fishmark 320 so naturally I turned around and tried to catch them from the front of the boat. But as I neared the area where I marked the fish I didn't see them on the X-16. In fact, I didn't see much of my spoon on the graph when normally its like an Etcha-Sketch and I can draw pictures on the screen with my spoon.
So I crank up the sensitivity and that doesn't help. I check to make sure the TM and transducer are pointing straight down. I check the connections on the back of the unit. I go thru all the settings on the unit. I even check the voltage and crank up the big motor and run the graph at 15+volts. No change.
Now I'm thinking I've got a bad transducer or even a bad unit and I'm resigned to the fact I've got to fish the rest of the day with the sensitivity cranked up to 99% and still not marking stuff that I know is down there. And then go and get the transducer replaced by Lowrance. (Its less than a year old) Or maybe the unit?
I'm fishin' and fumin' when a deja-vu like thought occurs to me that I've been there before. I was on my partner George's boat and his X-97 was having a similar problem not marking stuff it should have marked. (His problem turned out to be a transducer) I was complaining about his graph not showing a tree we were sitting on top of and he told me to do a full system reset to see if that helped. Well, it didn't on his boat. But I figured I didn't have anything to lose so I did one on my graph and reset all the options to the default values. Viola! I've got shad, I've got fish on the bottom, I've got my spoon drawing pictures on the screen again. And they weren't there a second ago!
Of course I lost all settings and now my depth is displayed in the upper left corner in 2 inch high numbers!
Moral of the story is, the graph is controlled by a computer, computers are programmed by people who make mistakes. I think my graph was confused and didn't recognize or use the settings I had input. It was in blue screen Never Never land just like my Windows o/s visits occasionally. The full system reset gave it a whack upside the head and brought the unit back to reality. Just like you need to reboot your computer once in a while.
Try it next time your graph is behaving badly.