No GPS signal on startup

Message Topic Search Topic Options Post Reply Create New Topic Printable Version Translate Topic

   Hello and thank you in advance for any assistance you can provide.
I fly a 2009 Vans RV10 equipped with dual Advanced Flight Systems 5600 EFIS, a Dynon AP (not Dyson per spellcheck), and an Avidyne 440 GPS/Nav/Com.  I do not know when the GPS was installed.

For several weeks now I am experiencing difficulty with "GPS integrity" on my EFIS screens, and a red X and no GPS signal or similar message on my Avidyne unit.  IFD Software version is 10.2.2.0.

IF I stay on the ground long enough the message goes away.  Forced reboots don't seem to help.  If I take off the GPS starts working during the flight.

My AFS/Dynon stuff has a VFR GPS, a dynon 250 I think.  This always has satellites when I check.

I've read that these symptoms are what can happen when an internal battery in the unit goes bad as the unit has to look for satellites afresh, with a good battery these things are remembered at start up.

The GPS does not fail in flight.

In this first video you see the message, GNAV 1 is the Avidyne unit.https://www.youtube.com/watch?v=kyzYHqmV6cU

In this 2nd video we can see where the Dynon GPS has signals at start up and the Avidyne does not.  https://youtu.be/hlr6AoMT2pQ?si=2TuHz9U_9OPZFKjF

So, is the internal battery causing my problems?  If so, how do I get it replaced, how much does it cost?  Is a loaner unit available?  How long does this take?

If this is not likely my problem, how do I troubleshoot this further?

Again, thank you.

Author	Message Topic Search Topic Options Post Reply Create New Topic Printable Version Translate Topic
N943MA Members Profile Send Private Message Find Members Posts Add to Buddy List Newbie Joined: 08 Jun 2025 Location: PGV Status: Offline Points: 3	Post Options Post Reply Quote N943MA Report Post Thanks(0) Quote Reply Topic: No GPS signal on startup Posted: 08 Jun 2025 at 8:58pm
	Hello and thank you in advance for any assistance you can provide. I fly a 2009 Vans RV10 equipped with dual Advanced Flight Systems 5600 EFIS, a Dynon AP (not Dyson per spellcheck), and an Avidyne 440 GPS/Nav/Com. I do not know when the GPS was installed. For several weeks now I am experiencing difficulty with "GPS integrity" on my EFIS screens, and a red X and no GPS signal or similar message on my Avidyne unit. IFD Software version is 10.2.2.0. IF I stay on the ground long enough the message goes away. Forced reboots don't seem to help. If I take off the GPS starts working during the flight. My AFS/Dynon stuff has a VFR GPS, a dynon 250 I think. This always has satellites when I check. I've read that these symptoms are what can happen when an internal battery in the unit goes bad as the unit has to look for satellites afresh, with a good battery these things are remembered at start up. The GPS does not fail in flight. In this first video you see the message, GNAV 1 is the Avidyne unit.https://www.youtube.com/watch?v=kyzYHqmV6cU In this 2nd video we can see where the Dynon GPS has signals at start up and the Avidyne does not. https://youtu.be/hlr6AoMT2pQ?si=2TuHz9U_9OPZFKjF So, is the internal battery causing my problems? If so, how do I get it replaced, how much does it cost? Is a loaner unit available? How long does this take? If this is not likely my problem, how do I troubleshoot this further? Again, thank you.

rpostmo Members Profile Send Private Message Find Members Posts Add to Buddy List Senior Member Joined: 20 Jul 2015 Location: North Dakota Status: Offline Points: 173	Post Options Post Reply Quote rpostmo Report Post Thanks(0) Quote Reply Posted: 17 hours 17 minutes ago at 9:27am
	Is your date set correctly on the Avidyne?

N943MA Members Profile Send Private Message Find Members Posts Add to Buddy List Newbie Joined: 08 Jun 2025 Location: PGV Status: Offline Points: 3	Post Options Post Reply Quote N943MA Report Post Thanks(0) Quote Reply Posted: 17 hours 7 minutes ago at 9:37am
	In one of the videos linked it shows the current date as October 19, 2005.

dmtidler Members Profile Send Private Message Find Members Posts Add to Buddy List Senior Member Joined: 12 Feb 2016 Location: USA Status: Offline Points: 632	Post Options Post Reply Quote dmtidler Report Post Thanks(0) Quote Reply Posted: 6 hours 8 minutes ago at 8:36pm
	It doesn't appear the GPS date rollover patch was ever done (Avidyne SIL 606-00182-019). This mandatory software patch was available starting in February 2019 and should have updated the AviOS 10.2.2.0 to AviOS 10.2.2.0.A. That patch should correct the date issue and may correct the other GPS issues including the continuous nav database out of date flags. Edited by dmtidler - 6 hours 6 minutes ago at 8:38pm