4S GPS does NOT work in any App

Take it to an apple store if you can.

Patrick J said:

Restored both as new phone and as backup. GPS worked in neither situation.

I think this points to a hardware failure?

In Portugal there are no Apple stores, and I want to avoid going through Vodafone. Where can I find an Apple number for portugal?

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Your warranty goes through Vodafone if you bought it there, and even though Apple offers supports, it's best to do this via Vodafone (because you may have issues later on, and than Apple might say "go to the store where you bought it", and Vodafone might say "this is not the iPhone 4S we sold you, it's got a different UDID".

Dumb question here, but you do have it turned on in settings right?

Could either be a software bug for you (hopefully) or it could be that the GPS antenna connection is intermittent (hardware failure).

Let's see how it works under a time of period, if it works flawlessly, no need to do anything about!

I wish you the best of luck.

Patrick J said:

15 minutes later I come back and see the Location icon on my menu bar. I fire up maps and it locates me perfectly. Same in the other apps.

Any theories as to what happened?

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Maybe a hardware problem, or a nasty software bug.

If it's a software problem, it sounds like the GPS lost track of where it was, and had to reinitialize it's location without wifi or cell tower triangulation assistance, which can take minutes with a good view of the satellites (e.g., outside). It can take even longer inside, or it may be impossible if you're somewhere that blocks the satellite signals (e.g., inside a stone room).

(Well, in normal operation, the GPS can also lose track if you turn off the GPS, move the iPhone some great distance -- as in tens to hundreds of kilometers -- and then turn the GPS back on. Without wifi or cell tower assistance, the GPS can take minutes to determine its location, and that assumes decent satellite signals.)

EDGE and GPS don't use the same wavelengths. You just happened to be in a location where GPS signal couldn't penetrate the walls well, but got lucky in a particular position.

Patrick J said:

Thanks for both your replies. What I find strange is that there was a ~24 hour interval in which the gps didn't work. Most of this time I was in fact in a stone house in the countryside, however, I had full EDGE connection all the time.

The hours before this problem I moved from Oporto to my country house ~150km (93miles). During the trip I didn't touch any location apps. I happen to have had all the "system services" turned off under Location Services, I wonder if this might have anything to do with it?

Stranger still is that it fixed itself without me taking it outside.

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GPS won't work if the satellite signals are blocked (by stone walls, etc.). Cellular signals (e.g., EDGE) and wifi can be used to estimate your location, but cannot be used to accurately determine your location. (This also assumes that the cell tower database is available/accurate in your country.) If available, this estimate helps the GPS quickly determine your location; without the estimate, the GPS takes longer to locate your position. (And this assumes that the GPS gets decent satellite signals, which it often cannot get inside a stone house.)

GPS satellite signals can often be received inside a house -- such as near a window or on the top floor of a building, if the roof does not significantly block the signals. Wooden roofs are often good -- stone or metal roofs are not so good. I don't know if GPS signals will go through tile roofs.

Your problem might have been caused by an unfortunate combination of moving a significant distance and being in a stone house. If it happens again, try using the GPS outside; depending on how far you've moved, and how long you haven't used the GPS, it may take 30 seconds to several minutes to determine your location.