Samsung Galaxy S4 Mini - GPS stops working after screen lock or app moved to background, why?

[AC Question]

Samsung Galaxy S4 Mini - GPS stops working after screen lock or app moved to background

Dear all, I have a problem with my Samsung Galaxy S4 Mini running android 4.4.2:

Whenever I use any application that uses GPS, the GPS works normally, but whenever the screen gets locked (either automatically after few seconds or with the lock key) or if I press the phone Home button, GPS stops working.
When I turn off and back on the GPS, it starts working again, however this is pretty annoying, since it should recover by itself.

I tried many apps like "GPS Status" and they just confirmed that the behavior is not app specific, but is related to the ability of the phone to lock to the satellites. As if the phone is unable to recover/restart the searching of the channels. Clearing the GPS cache did not help.

Any help is highly appreciated.

 

[Rukbat]

Re: Samsung Galaxy S4 Mini - GPS stops working after screen lock or app moved to background

It sounds as if the GPS receiver itself is being turned off when you lock the screen. If you're getting 30 seconds or less to a GPS lock, that's a warm start, and it means that GPS was turned off. (If all GPS data had been cleared it would take much longer - it would be a cold start, and the GPS would first have to figure out which satellites to be looking for.)

Why it's being turned off? No idea. You could have an app doing it. Start in Safe Mode:

With the device powered off, press and hold the Power button (located on the right edge) until the 'Samsung Galaxy S® 4 mini' screen appears then release.

With 'Samsung Galaxy S® 4 mini' still on-screen, press and hold the Volume Down button (located on the left edge).

Continue to hold the Volume Down button until 'Safe mode' appears in the lower left of the unlock screen then release.

Note This may take up to 30 seconds.

Now allow it to lock, unlock it and run GPS Status and see if it locks in a few seconds. (An app isn't not going to remain locked if you turn the app off, then turn it back on - it has to wait for the next output from the receiver, which can take 2 or 3 seconds before it shows your location. No GPS, cellphone or standalone, generally updates more than once per second. The satellites don't transmit your location - there's a LOT of math going on between receiving the satellite signals and determining where you are.)