Raymarine E120 loosing fix

[Jurgen]

Hi all,

I have a Raymarine E120 classic plotter that keeps loosing GPS & AIS fix which then produces a lost fix alarm which happens every 5 minutes or so. This is rectified by pressing the acknowledge button and after a moment the GPS & AIS fix is regained.

This happens continuously and is seriously annoying.

Have looked at the various connections and all seems to be good, any advice is much welcomed.

Andy

 

[oGaryo]

Hi all,

I have a Raymarine E120 classic plotter that keeps loosing GPS & AIS fix which then produces a lost fix alarm which happens every 5 minutes or so. This is rectified by pressing the acknowledge button and after a moment the GPS & AIS fix is regained.

This happens continuously and is seriously annoying.

Have looked at the various connections and all seems to be good, any advice is much welcomed.

Andy

Andy, have you tried a firmware upgrade to the plotter in case it's something like this?

http://formulaboatsforum.com/forumtest/index.php?action=printpage;topic=2225.0

What does the light on the GPS tell you when you lose the fix?

 

[Ripster]

I had this happen on a previous boat. Raym kit. Mine was blamed on the GPS Mushroom being at fault, so I borrowed one and the fault was the same. It turned out to be a dirty/poor connection on the plug going into the back of the MFD unit. I had cleaned everything at the mushroom end and the fault was still there as said. Was about to try a new cable, but before, just scrubbed all the pins a bit and tested and it never did again. I know you said you looked at connections, but before buying any kit, the connections may be worth a 2nd look.

 

[Elessar]

The GPS mushroom is a digital yacht NMEA unit.

It feeds the VHF DSC and the AIS unit at 4800 baud - but there is no direct connection to the E120.

The AIS unit passes the the GPS signal through, and upgrades it to 38400 baud.

The E120 baud rate is then set to 38400. This is because the E120 has only 1 baud rate setting which does both the in and the out.

Otherwise you'd set the in to 38400 for the AIS and the out to 4800 for the VHF DSC.

So, as the VHF is not losing fix, the mushroom must be OK. The power supply to the AIS unit is a push in round thing with no positive retention - I'd start with that. If you take the grill off is it possible to let the AIS dangle out of the dash? it has a red power LED and a green data LED. Migh give you a clue.

If that doesn't work set the baud on the E120 to 4800. The AIS will stop working, but that should give you a solid fix. If so, the fault is in the wiring to the AIS unit or the AIS unit itself.

That's if there's a direct NMEA connection from the mushroom to the E120 - I think there is but can't be sure - if there is no fix at 4800 there isn't and you need to make one to eliminate the AIS.

 

[AndieMac]

I've heard of this issue occurring with the E120's when say, a satellite phone is turned on and the antennae's are close by each other.

 

[Jurgen]

I had this happen on a previous boat. Raym kit. Mine was blamed on the GPS Mushroom being at fault, so I borrowed one and the fault was the same. It turned out to be a dirty/poor connection on the plug going into the back of the MFD unit. I had cleaned everything at the mushroom end and the fault was still there as said. Was about to try a new cable, but before, just scrubbed all the pins a bit and tested and it never did again. I know you said you looked at connections, but before buying any kit, the connections may be worth a 2nd look.

Hi Rip, I did notice some corrosion on the multi pin plug going into the AIS, the 1 that looks like a PC monitor lead. Will take it off and try cleaning but will also look at the other solutions.

Is really odd as all was working fine when the boat came out so very odd.

 

[Jurgen]

The GPS mushroom is a digital yacht NMEA unit.

It feeds the VHF DSC and the AIS unit at 4800 baud - but there is no direct connection to the E120.

The AIS unit passes the the GPS signal through, and upgrades it to 38400 baud.

The E120 baud rate is then set to 38400. This is because the E120 has only 1 baud rate setting which does both the in and the out.

Otherwise you'd set the in to 38400 for the AIS and the out to 4800 for the VHF DSC.

So, as the VHF is not losing fix, the mushroom must be OK. The power supply to the AIS unit is a push in round thing with no positive retention - I'd start with that. If you take the grill off is it possible to let the AIS dangle out of the dash? it has a red power LED and a green data LED. Migh give you a clue.

If that doesn't work set the baud on the E120 to 4800. The AIS will stop working, but that should give you a solid fix. If so, the fault is in the wiring to the AIS unit or the AIS unit itself.

That's if there's a direct NMEA connection from the mushroom to the E120 - I think there is but can't be sure - if there is no fix at 4800 there isn't and you need to make one to eliminate the AIS.

Hi Mark,

Will try your suggestions and see if they have any effect.

Regards

Andy