585 not seeing p66 transducer

[bogie418]

One day out fishing the head unit quit 'seeing' the transducer signal. It was reading the bottom like normal then it kinda lost its mind. It cycles thru different depths every couple of seconds like its hunting around for a signal.(something like 2500ft, 600ft, 15ft) If I plug in the 10 pin connector into the back or leave it out, the screen cycling is the same.
The p66 cable was cracked and corroded under the waterline where it enters the transducer. I replaced it. The same thing is happening with the brand new p66.
All the buttons and dials work.
ROM :OK
SDRAM: OK
NEMA:
TEMP: 50.2 F
SPEED: 0.0
POWER 12.6 V
ECHO: 1048576
The echo goes from 1048576 to 3, back and forth
Any ideas?

 

[C-Bass]

Good morning Bogie418,

Thank your inquiry.

I have a good idea what is going on. Is your FCV585 set to the Auto Range mode? It likely is and what is happening is the sounder is searching for bottom. When it does not see the bottom or does not see a good bottom return in Auto Range, the sounder will go to a deeper range scale and try to find the bottom. If it does not find a good bottom return it will cycle to the next range scale and try again. So what is happening, is the transducer is likely experience turbulence and the water flow over the transducer is likely not good. The sounder is searching for bottom but cannot get a good bottom reading because of the turbulence.

You could take the sounder out of the Auto Range mode and put it into manual range. Choose a range that is deeper than the water you or in. If you don't choose a range deeper than the water you are in the FCV585 will not know where the bottom is. That is ok for some fishing techniques but it may not be what you are looking for. So if that is the case please choose a range that is deeper than what the bottom is, so the sounder can show you the bottom on the display.

Does this happen when the vessel is not moving? If hold the vessel in a neutral position and turn the engine off, does this continue to happen?

You may need to either adjust the angle of the transducers to make sure that is is looking straight down or choose another mounting location on the transom.

C-Bass

 

[bogie418]

I messed around with the setting the day it quit out on the water. I had a good idea i was in 100 feet of water and played with the buttons for about 20 min before i gave up.
Now im out of the water on the trailer in the back yard. The old transducer would read the lawn at 4 ft.
Do you know if there is a circuit board fuse that might have popped?
I wonder if a ‘normal’ 585 head unit would act the same way when the transducer is unplugged?
Thanks for the reply

 

[C-Bass]

In auto range mode a different 585 would react the same way with no transducer connected.

 

[bogie418]

Does anyone know where to get a diagram of the circuit board components? My best guess is a blown circuit board fuse?
Or pehaps somewhere i could send the head unit for repair?
Thanks

 

[Snips]

Bogie418,
The FCV-585 doesn't have an internal fuse. A couple other things to try is a master reset (Restore settings), you should find this in the bottom of the menus. One check you can do to see if the sounder is transmitting is to wet your fingers and slide them over the face of the transducer. Normally you will be able to feel the TX pulse as the sounder transmits.

Snips