GPS unit acquiring satelites forever

[phorvati]

I have a Garmin 120 GPS with external antenna. It has a BNC connector for the antenna. As of few days ago it cannot acquire any sattelite signals. I suspect someting is wrong with the antenna wire or antenna itself. Is there a way to test at the BNC connector if antenna is working?
Petar

[Alan Wheeler]

Easily Only with another reciever. You might find it as simple getting a replacment Antennae and replacing it. It is mostly likely the cause of the problem.
As the BNC connector gets the most abuse at the cable/connector joint, you may wish to redo this connection. Apart from that, cables just don't just fail unless you have a large verticle hang that is unsupported. Like up the mast. Then the weight of the cable over time can cause failure.

I am presuming nothing has changes around the antennae. You haven't placed some object that is now "shading" it's view of the sky?

[phorvati]

No, I havent changed anything. All of sudden, It stopped working. I re-spliced ththe BNC connector at the unit, and its not it. The power cable, the 7 prong cable with power, ground, NMEA In/Out and the rest, sometimes has a bad connectivity. If I wiggle it a bit the GPS looses power. So I fixed it to the bulkhead with wire ties so it doesn't move. But that is not the Antenna cable. However, cthat have something to do with it?

[AnchorageGuy]

Peter, Some of the external antennas have a led light telling you if the sats are acquired or they flash an error code. If yours does not do this then I am afraid you will probably need to send the unit and the antenna back to Garmin for service. Give their tech support a call on Monday and they will either walk you through a reset which sets the unit back to all factory defaults or instruct you to return it and give you an RMA number. Fixing a loose connection by securing the cable is just not going to work. If you can not fix the connection then you might consider replacing the cable from Garmin.

[delmarrey]

I found with mine if the batteries are not up to snuff it will not acquire until I start the motor and it's running off the alternator power. Once it has acquired then I shut down the motor and it continues.

Yeah I know, I need new batteries. They're only 4 years old but for now I'm just harbor crusing. But that's the case..........................._/)

[phorvati]

Bad news. I got the new antenna but it still has the same probem. Acquiring sattelites forever. I opened the unit to see if there is a broken wire at the connector of the panel but no. I have continuity all the way to the circuitboard. My next guess is that it might be the software. Unfortunately this is a discontinued product and there are no software updates on garmin website? Does anyone know if I can get the software update from somewhere else. The model is GPS120

[merlin]

Just my 2cents, I have owned a couple of Garmin GPS units. If the unit all of sudden stopped working then something may have happened to the unit. I wouldn't think it would be the software.

I would call Garmin, they have pretty good customer service even for products that are no longer being made. They may be able to help you troubleshoot your issue.

[GordMay]

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[Wahoo Sails]

Two things, on many of the older Garmin units, there was a "self test" page .... something that was not in the owners manual. Typically, you would hold down the "page" button then turn the unit on (sometimes it was the "enter" button) it would pop up a screen that you had never seen before, one of the things on that page was a "pass / fail" test of the antenna. The other thing was "lost almanac" if the unit had been shut off for many months, it would "loose it's almanac" ... highly technical fix for this .... turn the unit on ... and walk away. I have seen it take as long as 24 hours of continuosly searching before the unit recovered it's almanac (gets this from the satellites) ... and then starts working normally again.
Bob

[GordMay]

Wahoo Bob:
Thanks for the GREAT TIP!

[Thermal]

I've had this happen to my garmin a few times as well - was always a "bad" almanac, either from being too old, or from using it last somewhere else in the world, far away. I think there was a way to force it to get a new almanac, but as whaoo said, it can take a very long time.

[phorvati]

I've had it on since my last post. I also had it on for more than 48hours cintinuously. I have plenty of juice in the battereis. Voltage never fell below 12V. Wahoo sails, pressing te page button while powering up resets the navigation mode to AutoLocate. I had it on Normal before. Pressing the Ent button while powering does the trick. It displays the test page. I pressed enter and a funny concetric circles come up. The numbers I have are following:
SWR 0.0
Sognal

I just got an answer from Garmin:
Quote:
"Thank You for contacting Garmin Product Support! I will be glad to help
you with this.
Unfortunately, there are no updates for this particular unit, and cannot
be repaired. I apologize for any inconvenience this has caused.
Best Regards"
I left the person's name unlisted.

signal 1925
drift -19.404
freq 16368318
temp 29
time 12:17:34

Would you know what to do with these numbers?

Oh one more thing. I just did the same test on my small handheld unit which is working, and the numbers were simmilar:
SNR 0.00
signal 1649

[hellosailor]

ph-
Forget about software updates, the software simply cannot make any difference regarding whether the GPS is seeing satellites. I don't know that model but Garmin uints all have some page that lets you "see" how many satellites have been acquied and what their strength is, if you are not able to acquire them at all, after 8 hours of a good sky view, then there is a hardware problem. If the hardware is working, the almanac problems (the ephemeris update) DOES happen once they get a good sky view for a long enough time.

The old units could indeed take almost an hour to acquire satellites if they were off for several months, or moved a thousand miles. Garmin claims yours is:

"
Acquisition Times:

• Warm: approx. 20 seconds
• Cold: approx. 2 minutes
• Autolocate™: approx. 7.5 minutes

"

Newer units do this in less than five minutes, and are now so sensitive that the "sky view" can even be through a simple boat deck or a thin home roof. Really incredible progress!

"signal 1925" seems to indicate that it is indeed getting a signal from the antenna, making it probable there's something else wrong. Most fo the Garmin units are in sealed cases, "welded" shut to make them water-resistant. If that's the same with yours, it is simply "economically unfeasible" for Garmin to split it open, do a repair, then install a new caase (if they are available). You'd be looking at a $100-150 repair versus the cost of a new unit. Looking at that GPS on the garmin site...I think a friend of mine has the exact same one. It certainly does the job, but getting a replacement (with internal or external antenna) won't be anywhere near as expensive as those used to be. If you really want an exact replacement, you can probably find a used one on eBay with a little patience. Or, upgrade to something more modern.

One other option I can think of, if you know how to solder. Open the case up, lift up the circuit board, and look very carefully for cold solder joints. Any type of hairline crack in a solder pool, any type of chip that might be unseated. I've found that an AWFUL lot of circuit boards fail from cold solder joints, and all you need to do is reflow the solder to get them fixed again. Since it costs nothing but a little time to try...Why not?

[Wahoo Sails]

Phorvati,
Sorry, I can't help you with understanding the numbers. The concentric rings are just one of the tests to see if the screen is working properly. Once again, pressing page (or maybe enter) and you will see other tests appear.
When all is said & done, the 120 is a very old unit & is now well beyond it's planned life expectancy. It's probably time to just put the poor beast out of it's misery. If you're like most people I know, you're hanging on to this older unit, not because of the money ... but because you already know how to work that one!
As I have mentioned earlier on other posts, I have been working at West Marine the last couple of weeks (monday will be my last day) right at the moment we have a few left over Garmin 492's ... at $499 ... 2 months ago the same unit was $899, the big price drop is because the unit is discontinued. Discontinued or not, it's a whale of a good deal! Once you have used one Garmin product, you will find the next one intuitive.
Bob

[phorvati]

Hi guys, thaks for replies. I feel confident soldering, and the unit is not welded shut but the chip itself is. I had it open many times to test the contunuity across the bnc connector. Unfortunately the continuity across the connector and varous accesible spots on the circuit board is good. I will spend some more time looking at the cracks. And perhaps put a drop of tin on any one of them I find. Bit it looks like its the hardware problem, and there are no updates for mine. The signal is questinable. The test page displays the same numbers whether antenna is plugged in or not ???
I had this unit on for 2-3 weeks without any changes in bars representing sattelites. While the sattelite signal is good on the test page.
anyway we have a hand-held unit which is our only hope in these remote areas. I think until we reach puerto rico or DR we have to hope that the handheld unit works. Then we'll see about getting another external antenna unit.
Petar