No GPS fix

[Streetwalker]

I know its a long shot but my chartplotter just decided it didnt want to recieve coordinates anymore. Everything else works fine on it, it just says " no fix" where the numbers should be. I checked all the wiring terminals & other connections & all looks good. Its a raymarine L 760 RC coupled to a Raymarine Seatalk 120 GPS reciever. Anyone know of any easy things to check before I have to take it in to get looked at ?

[Draggin' Bait]

If the wiring all looks good I'd drive or tow it a half mile away and try again. You might be in an area getting some kind of signal bounce confusing the computer. Another area with a clear shot at the sky and no "bounce" and you might be OK. If it isn't that simple, try borrowing another antenna and plugging that in for a test. Last year I accidentally created a spark while working on my boat (forgot to disconnect the battery even though everything was off -- arrgh!). It rocketed around the boat and popped half a dozen fuses plus it fried my gps antenna. The symptoms were the same as yours -- unit lights up but cannot get a fix. The test antenna the local tech had produced an almost immediate fix. So, I ordered a new antenna. The plus side (a few bucks later) was that the new antenna is about six years newer and I actually get fixes much better with the new antenna than the old one when the weather is less than perfect.

[blubeast]

You might want to check your owners manual... and do a factory reset... then wait for signal re-capture.

In doing so you may loose your stored coordinates, so write them down first.

[ISeeFish]

I have read that the Seatalk 120 has a known problem. Do a search on thehulltruth.com.

[Streetwalker]

Well, it started working agian last weekend. While that should seem like good news, it worries me. I'm afraid it may be an intermittent type thing that may be impossible to diagnose. I know that location wasnt the problem before becuase I wouldnt work in locations that were mile apart. I think I may just have it replaced. In the mean time I do have a handheld backup. I think I'll do a little research on the problems w/ them. Thanks for the site tip !

[GRUMPYR]

If it wasn't turned on for a long stretch, it may have just needed to capture an up to date almanac. Some times that will take up to 30 minutes. At least that's the way the aviation units work.
G

[BiteFactory]

Good point about the satelite position almanac that it needs to download sometimes.

If your GPS is older, it's internal battery can wear down which will cause the memory to loose the almanac when it is turned off. If this is the case you'll see "aquiring satellites" or "searching" for a good while (up to 30 minutes maybe average?) and then it will work fine until it is turned off again. Saw this happen in an older IImorrow handheld last year.

[Streetwalker]

Turned it back on in the driveway after coming home & it fired up fine, its only 3 yrs old. I'm afraid I may have an intermittent connection problem in a place I cant see or the reciever is just giong bad. I'll either have to wait till it does it agian to get it diagnosed or drop a boat buck on a new reciever.

[TrinhTD]

I had a similar problem with my Magellan Map330 GPS last year.

I was trying to get to my Halibut markings at Neah Bay on my way out and the GPS kept showing that I was somewhere in South America. It was working fine before I get to Neah Bay. I checked it again on the way back from Neah Bay and it was working again. Made me really mad since I could not find my way to the fish.

It works fine ever since.

I was wondering if the Gov. was temporary shutting down the satellite on that day.