Internal GPS problem

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pgroell
Posts: 11
Joined: Wed Mar 13, 2013 4:26 pm

Internal GPS problem

Post by pgroell »

Hello,
I have a dual Sport panel.
On the left a Sport SX (upgraded from Sport HS) and on the right a Sport HS with internal GPS.
For some time now the internal GPS is not getting any fix and giving an error after some time (No GPS1 data from Serial 3).
I tried the antenna from my Garmin Aera 550 without success.
The setup is :
Left EFIS
Serial 1 input: NMEA GPS 1 which is the Garmin Aera 550

Right EFIS :
Serial 3 input: NMEA GPS 1
Serial 3 output: NMEA GPS 1

Any clues?
Thanks
JimB
Posts: 87
Joined: Tue Mar 12, 2013 12:52 am

Re: Internal GPS problem

Post by JimB »

Try setting the gps on the right EFIS to GPS2. There may be a conflict with both being named GPS1.

Is the serial counter on the right Efis counting? (In General Setup you should see the counter)

There is a way to view whether the internal gps is "seeing" satellites. I think it is on the Display Unit Maintenance page.

Let us know what you find.

Jim Butcher
pgroell
Posts: 11
Joined: Wed Mar 13, 2013 4:26 pm

Re: Internal GPS problem

Post by pgroell »

Hello,
Well, it worked with those settings for almost five years.

I already tried a few things :
- renaming to GPS 2, no change
- isolating the EFIS from the other : I sometimes get a fix, no satellites on the GPS display page and after a few seconds I get the error message.
- the serial counter is counting for some time, then it stops and there is the error message

See the picture taken during one of the tests.

http://www.notreavion.net/uploads/GPS1.jpg

I have ordered a Garmin GA25 antenna and will see if that can solve the problem, I will also do all further trouble shooting with only the EFIS with the internal GPS powered up to see if I find something.
Anyway, thanks for your input.
JimB
Posts: 87
Joined: Tue Mar 12, 2013 12:52 am

Re: Internal GPS problem

Post by JimB »

The internal GPS plugs into a board in the EFIS. You might try opening the case and reseating it.

My internal GPS sometimes works and sometimes doesn't too! I just rely on my GNS 430 GPS.

Jim Butcher
GRT_Jeff
Posts: 802
Joined: Tue Dec 11, 2012 12:11 am

Re: Internal GPS problem

Post by GRT_Jeff »

A "No GPS# DATA FROM SERIAL #" alarm means the GPS stopped talking completely. This could mean someone accidentally wired something to Serial Port 3 Input pin 32 (RX3), which would interfere with the internal connection to the GPS. Your picture shows some data from the GPS, but the data is not complete (no satellite plot). A bad antenna would not cause communication errors, and should not cause a complete failure.

I don't understand why Garmin is selling the GA 25 now and not the GA 27. In the past they pulled the GA 25 because it had interference issues and told us to use the GA 27. Now it looks like they don't sell the GA 27 anymore. Hopefully they improved the GA 25.
pgroell
Posts: 11
Joined: Wed Mar 13, 2013 4:26 pm

Re: Internal GPS problem

Post by pgroell »

Hello Jeff,
thanks for your input.
I will do more tests during the week and come back to you if I find something.
As for the antenna, it is the only one I found in a short time here in Europe to perform some tests.
Regards
pgroell
Posts: 11
Joined: Wed Mar 13, 2013 4:26 pm

Re: Internal GPS problem

Post by pgroell »

Hello,

so I performed a few more tests, the results are not very good.
Only once in about twenty boot up tests did the GPS see satellites but the after a few seconds the serial connection failed again.
On the other tests the GPS did not even see satellites, and went either to FAILED in the Status page or stayed FLAGGED for some time before failing.
Seems either the internal serial connection is not working or the GPS module is not working anymore.
What would my options be?

Pascal
GRT_Jeff
Posts: 802
Joined: Tue Dec 11, 2012 12:11 am

Re: Internal GPS problem

Post by GRT_Jeff »

I'd want to test it with a simple power and ground cable (no other connections except the antenna). That is the first test we would do here to try to confirm the problem. If we can confirm the problem, then we would inspect the connectors and ribbon cables that connect the GPS to the main board. If we didn't find a problem there, we would try replacing the GPS. Last I checked, a GPS repair that required replacement was around $150.
pgroell
Posts: 11
Joined: Wed Mar 13, 2013 4:26 pm

Re: Internal GPS problem

Post by pgroell »

Jeff,

thanks for the answer.
I will fly the summer season with the problem (which is not really one as I have other navigation sources).
I will later perform the simple test you suggest, if I still have the problem I will send the unit back to you (maybe also have the CPU upgraded at the same time).
The fact that I am in Europe make this a bit more complicated.
Best regards

Pascal
Harv1358
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Joined: Mon Aug 26, 2013 12:55 am
Location: 53012, Cedarburg, WI
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Re: Internal GPS problem

Post by Harv1358 »

I also have a dual Sport panel. On the left a Sport SX (upgraded from Sport HS) and on the right a Sport HS with internal GPS.
I also on and off am having the same problems. For the past couple of months, the internal GPS is not getting any fix and give an error once (No GPS1 data from Serial 3). Went up today,
working fine. At this point not sure were to look or what to do. I unplug the antenna and plugged it back in. Sometimes works and sometimes not. Don't know if I should of had the GPS put into the
New upgraded Sport SX unit. Might of been a better GPS or more Reliable?
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