Raymarine Lost Its position

[Doods]

Been one of those weekends
First run out since November and weather was great, only problem is the chart plotter stopped working. I have a Raymarine C120 and this weekend its managed to loose its GPS reception. I have had the unit out and checked all the connections and all looks ok. The unit works ok so it must be the actual "Mushroom" on the roof.
Question :- does the mushroom / aerial have its own power supply and could this be the problem, or is it possible to test the mushroom / aerial on its own to check its working. Of course the third option is I am completely wrong and it could be something else.

Any info from those that know would be greatly appreciated

 

[jfm]

Been one of those weekends
First run out since November and weather was great, only problem is the chart plotter stopped working. I have a Raymarine C120 and this weekend its managed to loose its GPS reception. I have had the unit out and checked all the connections and all looks ok. The unit works ok so it must be the actual "Mushroom" on the roof.
Question :- does the mushroom / aerial have its own power supply and could this be the problem, or is it possible to test the mushroom / aerial on its own to check its working. Of course the third option is I am completely wrong and it could be something else.

Any info from those that know would be greatly appreciated

The mushroom isn't an aerial; it's a full GPS engine. It would be handy to know which mushroom model you have, to narrow things down a bit. If the mushroom is recent (about 2006 onwards) it'll have a multicolour LED on the top to tell you it's status.

It could and likely does have a separate power supply. The mushroom is powered by the Seatalk 1 bus, and normally boats are wired so that the 12v power supply to that bus is from an independent source. Usually the source is the a/pilot computer if you have a Raymarine a/p, otherwise another 12v supply from the boat

If the mushroom has the 2006-onwards LED you can test it by applying 12v to it independently and seeing what the LED tells you. (download the manual, as there are minimum 3 wires (possibly 6 iirc) so you need to know which is which). If it has no LED you can only* test it by seeing if it emits a Seatalk 1 signal, so you need to connect it to the Seatalk 1 bus and use your C120 or some other Raymarine gear on the boat to read its output.

(*You could use an oscillscope, or a sensitive 5v DC meter, to see if there's a signal on the yellow wire I suppose, but it's easier to plug it into the seatalk 1 bus.)

A further possibility is that you have the version of the mushroom that talks a NMEA0183 signal. I doubt it, if you have a C series, but it's possible. If so, none of the above applies. Shout, if this is the case

 

[jimmy_the_builder]

Been one of those weekends
First run out since November and weather was great, only problem is the chart plotter stopped working. I have a Raymarine C120 and this weekend its managed to loose its GPS reception. I have had the unit out and checked all the connections and all looks ok. The unit works ok so it must be the actual "Mushroom" on the roof.
Question :- does the mushroom / aerial have its own power supply and could this be the problem, or is it possible to test the mushroom / aerial on its own to check its working. Of course the third option is I am completely wrong and it could be something else.

Any info from those that know would be greatly appreciated

Have you got a dsc vhf? Is it getting a position?

Cheers
Jimmy

 

[scubaman]

We had a similar problem on our F37 two years ago. Our problem was caused by a faulty connection which cut out the power from the Seatalk and the GPS. According to Sealine, the connection should have been in a box in the port side of the lazarette. After much digging I found the connection from the white plastic rail that runs the wires to the back of the lazarette. It was an ordinary sugar cube type of connector that had got wet and subsequently the leads were oxidized and connection was lost. This was easily solved with a new connector.

Pardon me for the lack of correct electrical terms, but I hope you get the meaning.

If my memory serves me right, the speed log blacked out as well (in the same Seatalk -loop). Are all your other instruments working ok?

 

[Talulah]

There is a CR2032 battery in the Raystar 120. 'Lost Fix' is a sympton that this needs replacing. It's not easy to replace as it is soldered to a mount.

 

[oceanfroggie]

"Raymarine Lost Its position"

Garmin took over the no 1 position some years ago

 

[Ursa Minor]

1st post here but if it's the Raystar 120 that you have, consider yourself lucky that it's lasted so long. The Raystar 125 is much more reliable however.

 

[Doods]

Thanks for all the info.
I believe that the unit is a RAYSTAR 120 as originally fitted, and from what you chaps and others have said I have been lukcy its lasted this long. I will have a check and test the battery. If that is the problem I will just change it however it may be just worh fitting a complete new GPS unit.
Any idea on what would be best option and costs if i do have to change it

Thanks

 

[Ursa Minor]

The battery probably only serves to retain the satellite almanac in the RS120's memory. If it was merely the battery that had died, I would imagine that the unit would eventually obtain a position fix, after 10-15 minutes.

The fact that this is not happening would suggest that unfortunately your unit is defunct.