Originally Posted by Ex-Calif
One of the gigs on the boat after refit is constant flashing of the depth with zero indicated depth.
The manual says this is a transducer fault. The transducer was working fine at haulout and I do have a spare (new) which I hooked up while on the hard with the same result.
I think I have the pinouts wrong.
The indicator/guage has red, shield and yellow - I am sure that's power, ground and seatalk bus.
The transducer has blue, black and shield. The original transducer had 2 wires and this is a later model transducer. The Raymarine FAQ site indicates that transducer black and shield are both connected to gauge shield and blue is connected to red.
That's how I have it wired. So I know I get power but I don't get signal. Here's a shot underway last Wednesday.
Any thoughts or wisdom of what to try next?
First, and foremost, the depthsounder cannot work when the boat is out of the water
If the unit powers up, means that the power connection is probably fine.
Verify power to unit is between 11 and 15 Vdc.
With power applied, place your hand firmly on the transducer face and slowly slide it across. You should feel it pulsing.
If not, you have one of 3 possible faults:
1. Defective display head
2. Transducer wiring/cable fault.
3. Defective transducer.
Best bet would be to put a scope
on the transducer connection. You should get a transmit pulse (about 300V p-p) every 1/2 to 1 second.
If it is pulsing, you have one of three possible faults:
1. Weak echo (check transducer installation).
2. Wrong frequency transducer.
3. Defective display head