GTN650 suddenly can't hold it's position

[Sig600]

Anyone seen this before?

My GTN650 has started just randomly losing satellites, and dropping position. Usually pulling the breaker and cycling the power will get it back. Yesterday it took several minutes to acquire. The satellite status page will just be grey bars going up and down, every now and then one will turn green then go away. Then, like it's had some stroke of brilliance they'll all light up and turn blue and I'm off. Then sometime later my Skyview will announce GPS1 FAIL and we're at it again.

At first I thought there may be interference but the antenna is located right next to the skyview antenna and the dynon holds 9 satellites while the Garmin is struggling.

This is a new development in the last few flights. Pretty sad if this $10K piece of gear is failing at 100 hours.

Thoughts?

[krw5927]

Sounds like yet another possible GA35 antenna failure. Do you have a friend nearby who would be kind enough to swap GPS antennas with you for a flight?

[rleffler]

Originally Posted by krw5927

Sounds like yet another possible GA35 antenna failure. Do you have a friend nearby who would be kind enough to swap GPS antennas with you for a flight?

I concur........

I went through very similar issues this past fall. The first couple times, power cycling would work in the air, then it wouldn't.

Unfortunately, I purchased mine too early and by the time I made my first flight, it was out of warranty.

1. Check for shorts in the antenna cable, wiggle the cable to attempt to find that rogue shield wire causing issues
2. Ensure that the connectors are properly terminated
3. Swap out the GPS antenna

I had a GA-35 that went bad. There is a rumor going around that a batch of them failed due to over torqueing the mounting bolts, causing cracks in the shell, then water getting into the antenna. I know that wasn't accurate in my case. I measured the torque and my RV hadn't been rained on.

I bought a new GA-35, swapped it out, and everything is just fine now. I had made the decision to eat any restocking fees if the problem persisted after the antenna swap.

I personally believe that Garmin had a bad batch of antennas a couple years ago. Because the warranty tends to expire on experimental builders before the first flight, they are now reaping the benefits by not having to replace these units under warranty. This is just another reason to purchase your expensive avionics at the last minute to maximize your warranty coverage.

[Walt]

I have found both the G3X team guys and the usual Garmin dealers will go way out of their way to help you correct issues like this and will bend the rules when justified to get you fixed up.

[rleffler]

Originally Posted by Walt

I have found both the G3X team guys and the usual Garmin dealers will go way out of their way to help you correct issues like this and will bend the rules when justified to get you fixed up.

I don't think that's universal with Garmin, but I do agree about the dealer participation. My dealer did go to bat for me and worked very closely with me in troubleshooting. They basically hit a stone wall Garmin due to the warranty period. It certainly had changed my perception (negatively) of Garmin support.

I don't think the G3X team was involved. I don't have a G3X, just a GTN650.

bob

[F1R]

Just curious if this happened with a 2020 ADS-B compliant system in controlled airspace and the failing antenna took out your second certified GPS system , would this cause a lost position for ATC, if and when they do away with SSR?

[Brantel]

I think it is important and in our best interest for us experimental guys to always work with/through TeamX.

While the GNS/GTN may not be in their department, they eat lunch with people that are responsible for those products.

It is important to realize that TeamX and the certified sections of Garmin are very different in nature but TeamX has proven that they will try their best to bridge the gap!

[Sig600]

Originally Posted by rleffler

I concur........

I went through very similar issues this past fall. The first couple times, power cycling would work in the air, then it wouldn't.

Unfortunately, I purchased mine too early and by the time I made my first flight, it was out of warranty.

1. Check for shorts in the antenna cable, wiggle the cable to attempt to find that rogue shield wire causing issues
2. Ensure that the connectors are properly terminated
3. Swap out the GPS antenna

I had a GA-35 that went bad. There is a rumor going around that a batch of them failed due to over torqueing the mounting bolts, causing cracks in the shell, then water getting into the antenna. I know that wasn't accurate in my case. I measured the torque and my RV hadn't been rained on.

I bought a new GA-35, swapped it out, and everything is just fine now. I had made the decision to eat any restocking fees if the problem persisted after the antenna swap.

I personally believe that Garmin had a bad batch of antennas a couple years ago. Because the warranty tends to expire on experimental builders before the first flight, they are now reaping the benefits by not having to replace these units under warranty. This is just another reason to purchase your expensive avionics at the last minute to maximize your warranty coverage.

My antennas are under the cowl, never been washed let alone rained on. Swapping the antenna sounds like the next logical step. I have an email out to Garmin, I'll post what I hear back.

[BobTurner]

Just to be sure, next time turn off the Dynon gps. It is possible for one antenna to interfere with another if it's the Dynon's electronics which have an issue. Not likely, but easy to check.

[Sig600]

I'll give it a whirl, but the fact everything worked perfect for 100 hours has me puzzled.