[Android Q&A, Help & Troubleshooting] robg37:
My wife and I got new Galaxy S II phones from C Spire earlier this month. They came with Android 2.3.6 out of the box, but a tech guy loaded 4.1.2 while we were still in the store. A few days later, I noticed a few odd things on both phones when using Google Maps:

With "Use wireless networks" checked, "Use GPS satellites" unchecked, and Wi-Fi off:

Maps plots my coarse location, so that I can see the blue directional arrow surrounded by a relatively large circle. So far, so good. But if I drive somewhere and keep Maps up, it never updates my position.​

With "Use wireless networks" checked, "Use GPS satellites" checked, and Wi-Fi off:

Maps plots my coarse location, just as above. The GPS icon appears and starts flashing in the notification area. Five minutes later, it will still be flashing. Again, if I drive somewhere and keep Maps up, it never updates my position.​

With "Use wireless networks" checked, "Use GPS satellites" either way, and Wi-Fi on:

Maps plots my coarse location, just as above. If I drive by a Wi-Fi network, Maps zooms over to the proper location, and the surrounding bluish circle is much smaller. However, after a few seconds, it zooms me back to my original position, and the much wider circle is back. And I know my car is incapable of teleportation.​

Here are the things I have done:

Used the Text CS service, was told to make sure I had a clear view of the sky, turn GPS off and back on, turn the phone off and back on, and finally to try a factory reset, which I eventually did and got the same results.

Tried several GPS apps for deleting and re-downloading AGPS data.

Talked to a C Spire sales person and tech person, called their customer service number, and talked to the tech guy who installed the updates to our phones the day we got them. He worked with it for a while, had me reset the phone through recovery mode (neither forms of resetting restored the original version of Android), and finally said he'd get us replacement phones. This shouldn't be taken as a rant against C Spire; all of these people were very friendly.

Went to my local C Spire store and got the replacement phones set up (they already had 4.1.2 on them, and I'm not sure if they came that way or if someone updated them). Exact same problem still occurred.

Did a chat with Samsung customer service. Had me restart the phone in Safe Mode, and that still didn't help. Suggested I call in and setup a support ticket, which I haven't done yet.

Our previous phones were both the original Galaxy S (SCH-I500). While the phones themselves seemed to bog down in their old age (and froze or reset themselves at least daily), the mobile network locating and GPS locating worked amazingly. Under decent conditions, the GPS might take 5 seconds to lock.

I finally had a bit of a breakthrough today, but it hasn't resolved the issue where location via mobile network won't update (scenario 1 in the numbered list above). I found out about GPS NMEA data, which, for those who have no reason to learn about such things, is the raw data transmitted to and from a GPS satellite and receiver, and installed GPS NMEA Tool. After starting the app, I waited for a bit, and still no GPS lock. The initial view presented by the app is a human-readable summary of the data, and at some point I opened up the raw GPS NMEA log. It started spouting off a few lines that looked to be saying "I can't find a dang thing," but suddenly all of that changed. I switched back to the summary view, and sure enough, I had a fix on several satellites. I exited the app, opened Google Maps, and it got a lock again. It didn't stay locked the whole time, and it was slow to update my position, but it did work.

As far as I know, GPS NMEA Tool is only a diagnostic tool that doesn't perform any magic fix to the phone. I thought this might just be a strange coincidence, but after being inside this evening, I took my phone back outside. I opened up Maps, and after a few minutes, I didn't have a lock. I fired up GPS NMEA Tool, and after a minute or so I had a lock again.

So, does anyone have any clue what might be going on? Here's the info on my phone:

Using an Otter Box Commuter case. I don't think it has any metal in it, and I think someone at a C Spire store tested the GPS without the case on.

Model: SCH-R760X

Android version: 4.1.2

Baseband version: S:R760.01 K.GB28

Kernel version: 3.0.31-980103

se.infra@SEP-129 #3

SMP PREEMPT Fri Mar 1 04:29:20

KST 2013

Build number: JZO54K.SCH-R760X.GB28

Hardware version: H:R760.01 K.Q

Software version: GB28

Mobile network type: EvDo-rev.A