I have a Garmin Nuvi 500 that I bought off eBay quite a few year ago.  It was in good shape when I bought it and had an extra mount and the original box.  I had to buy a lifetime map subscription in order to be able to reload maps to keep it current.

A few years ago it started showing an arrival time that was always an hour sooner than you would actually arrive - it was an issue with the satellite data when the time codes were refreshed in the satellites.  Evidently the time and/or date codes had reached their upper limit and the codes were started over.  Garmin sent notice that the Nuvi 500 was too old for them to keep providing support, and they no longer were sending updated Firmware - it was likely that the arrival times would be inaccurate.

I could deal with adjusting my arrival time when it was off by exactly one hour.  The little Nuvi 500 is great for my motorcycle - I mounted a plastic ball mount on the top of my forks and I can just pop the suction cup attachment off the mount and stick it on my Savage and clip in the Garmin.  The Nuvi 500 is completely waterproof and the internal battery lasts 5 or 6 hours without being hooked up to a power supply.  I use it in my car when I am not using it on the bike.

Several months ago the Garmin showed some operational distress.  The unit did not automatically switch from day to night mode on it;s own.....I had to do that manually. (Not a big deal but somewhat of a warning sign).

One the way down to NC last week I called up the stored "Deal Gap" location and the Garmin calculated the route....just for fun I also used the Iphone navigation.  For some reason the Garmin showed an arrival time that was 20 minutes later than the Iphone route.......I was curions to see which one was correct.  About 3 hours into the trip the Garmin display got weird - the display just showed "Continue on I-75" with no indication of how many miles to the next turn - it also stopped showing any features on the screen.....no other streets, buildings, lakes, speed limit or any information that indicated the unit was operating other than showing the current vehicle speed and direction.

I tried shutting the Garmin off and then reloading the destination - it didn't help.  I tried other destinations and searches and nothing improved.

When I got home I started looking for any possibility of repair, as I really like this little Nuvi 500.  I didn't want to spend money to buy another one as there is no support from Garmin, and I would have to buy another Lifetime Maps subscription if I got another one.  I used the Garmin Express program on my computer and tried reloading the maps - the program had a hard time finding the Nuvi and when it eventually did, the map update appeared fine for the 1.5 hours it took, then at the end it displayed an notice that an error had occurred (I tried several times and each was not successful).   I found out you can do a reset that clears all the stored data by holding your finger on the lower left side of the display screen while you power the unit on - the Nuvi still had trouble connecting to the computer and the map upgrade displayed the error code each time.  I downloaded the Garmin Express program to my newer laptop and the download ended a bit different without the error code being displayed - but the Nuvi still did not work.

In one last attempt I removed the battery and let the Nuvi sit overnight, then put the battery back in and did a reset to clear out all the data that was in the unit.  I then hooked it up to the computer and did a map update.  Immediately it was obvious that things were different as the Garmin Express program hooked up with the Nuvi immediately - I had previously always had difficulty getting the computer to recognize it was plugged in.  When the map update was over and I turned it on the display showed the entire United States Map and that seemed a bit weird - but then I realized the unit had not yet locked into the satellites to know where I was.  The unit quickly locked into the satellites and shows my location.  The unit was making sounds when I pushed buttons and when I entered a destination it locked in and started giving directions - complete with voice commands which it had never done before!

Over the last few days I have been testing it out around town.  The Nuvi works better than ever!  The daytime/nighttime mode changes automatically again, the unit finds satellites faster and calculates routes faster than it did before, and the arrival times are not correct after I set the local time.  I have muted the voice so that the battery life is longer - I can't hear the directions on the motorcycle anyhow.  (This old unit does not have bluetooth like the more modern motorcycle GPS units do).

So the end result of this long report is to warn you that if you GPS until freaks out and stops working - try removing the battery!  I was just about to give up on getting this Garmin to work again, and the battery removal was not something that I immediately considered as a repair process - but it was the magic trick that worked!

If that doesn't get it, open it up and look for an internal RAM protection battery.
You can also look for a Reset button. But if you find it and use it, it should go back to Out the box configuration. Maybe even with less stored.

Not that I've dealt with those, but I fixed copiers and cash registers for some years.
You may need to put it in a medically induced coma..

sent notice that the Nuvi 500 was too old for them to keep providing support, and they no longer give a schitt.

Yeah, everyone has heard that from Someone. It's not that big of a deal till it's your
Doctor.

Not judging anyone..
Said EVERY judgemental jakkass Ever..

I am just thrilled I was able to recusitate this little Garmin.  It is small and fit really well on the Ninja 250 and the Savage Cafe' - plus I keep it in the console of my car for when I get lost.  I was just about to give up on fixing it when the "remove the battery" idea crossed my mind.  I wonder how many GPS units have been thrown away as "non-working", when a battery removal might have fixed them as well?  The main reason I posted this was to let folks know that they may be able to get their GPS working again.

I don't use the Garmin when I am riding around where I live - but it is really helpful to have a GPS of some sort when we are riding in unknown areas and trying to follow the routes we have planned for the day.  I don't focus on the Garmin - but I do watch to see how many miles to the next critical intersection or change in roads.  It allows me to concentrate more on enjoying the ride and worry less about getting lost.