Backcountry Pilot

[Glidergeek offline]

Yesterday I couldn't get my Garmin 496 to acquire any satellites. Made my flight without it and last evening I scoured the owner's manual to no avail to find the solution. I emailed the person that I bought it from (Ebay buy it now $1395) asked him if he ever had a problem like this with this unit. He replied NO and forwarded this link to me. Hope this is useful to anybody getting ready to send theirs to Garmin with a $400 fixit fee.
http://www.vansairforce.com/community/s ... hp?t=32265
One thing I noticed before the reset the time was not right until I did the reset.
Glidergeek

[Bonanza Man offline]

If you have Narco Mk 12D radios and one of them is set to certain frequencies it can make the GPS inoperable. One of the freqs is 111.5, that is one of our ILS freqs here. I can flip flop between that freq and any other and watch the satellites go from full strength to zero sats in about 5 seconds. Other radios may produce similar problems. My 496 has never had a problem other than this one.

[a64pilot offline]

Mine does it all of the time, when it comes up and ask you if you want to run it in simulator mode if you select "stored without batteries", it will download the satellite almanac and then find itself. Often mine is turned off in Costa Rica or somewhere and the next time it is turned on, it's several thousand miles away.
It has locked up in flight before too, screen froze, and to get it back I had to unplug it and remove it's battery, it wouldn't even turn off.
Bonanza man, you can't tune a civilian radio to navigation freqs can you? Or are you saying a receiver will mess up the GPS too?

EDIT, mine is a 396, but exhibits the same symptoms

[Bonanza Man offline]

I do have a handheld I can try but haven't yet, I have the Vertex 700, the one that allows me to use the 2M ham freqs. It's my understanding that the problem is specific to certain nav/comms. For example if you tune a Garmin 430 or KX 155 to 111.5 it won't cause the problem with the 496. You can minimize the problem somewhat by using the external antenna for the 496 and playing with where to place it on the top of the panel.

[mtv offline]

I had the same problem with a 396. Called Garmin. Tech rep said it had sat too long without locating satellites. Had been a while Dang weather.

He recommended a hard reset. I asked about an internal memory battery. He responded that there is one, but it should last a loooonnnggg time, much longer than the three years I'd had the unit.

He also recommended I install the latest software updates from the internet.

I uploaded the new software, did a hard reset, and it's been good ever since, even though it's sat for a couple weeks at least once.

MTV

[Zzz]

I think many people kind of shine the software updates, but they do fix many of the known problems.

Download and install this.

Plug your unit in, it will find and identify it, and execute the update. It will reboot a few times and then let you know the update is finished. The instructions are pretty easy so just follow them

[Glidergeek offline]

Funny thing is I drove home with it and turned it off same place I turned it on and only overnight. I've down loaded all of the current software just last week. How do you do a hard reset?

[Zzz]

From the Garmin Support pages at garmin.com:

<div class="forum_news_column">
Question: Why does my Aviation portable GPS show the incorrect date and/or time when the unit is first turned on?

Answer:

The date and time being incorrect can be the result of several different issues, (ie, old almanac information, out of date software, corrupt software, and low clock battery).

If the GPS has not been used and allowed to acquire satellites within the last three weeks then follow these steps:

1. Plug the GPS into a wall outlet with the unit on and allow it to charge for eight hours

2. Perform a satellite reset: Start with the GPS off, a good antenna, and a clear view of the sky. Press and hold the ‘Out’ button then turn the GPS on using the ‘Power’ button. Continue to hold the ‘Out’ button until the “I Agree” message appears on the GPS. Release the ‘Out’ button and allow the GPS to acquire satellites for at least 15 minutes.


If the GPS is used on a regular basis but continues to show the incorrect date and time after power on then follow these steps:

1. Update the operating software to the latest version through www.garmin.com

2. Plug the GPS into a wall outlet with the unit on and allow it to charge for eight hours

3. Perform a reset: Start with the GPS off, a good antenna, and a clear view of the sky. Press and hold the ‘Quit’ button then turn the GPS on using the ‘Power’ button. Continue to hold the ‘Quit’ button until you see a message on the screen about deleting user information. (If you have not backed up the user information and want to do so you will need to download this information prior to completing this reset as the reset will delete user information.) Release the ‘Quit’ button and highlight the “Yes” and press the ‘Enter’ button.

If the unit continues to have the incorrect date and time after these steps then contact Garmin Aviation Technical Support at 1-866-739-5687, M-F, 7-7, CST.
Last modified on: 11/21/2008</div>

The "charging for 8 hours" part is probably not that critical.

[GumpAir offline]

phpBB2/viewtopic.php?p=37606#37606

Try this thread for some more info.

Gump

[MikeMl offline]

Yesterday I couldn't get my Garmin 496 to acquire any satellites...
Glidergeek

Try it out of the aircraft, running on internal batteries and stick antenna. If it aquires normally, then something in the aircraft is clobbering it.

Then try it back in the aircraft with all avionics in the aircraft turned off.

Find the Utility Page that shows the Signal-to-noise ratio for each of the satellites in view. While watching the SNRs, turn on each item of avionics. If one of the avionics item is the culprit, you should instantly see a reduction in the SNRs when the offending avionics item is turned on. On the Nav & Comm receivers, try tuning different frequencies.