Help GPS fix S5 - Dummies Guide

[gligeti]

I searched the web for anything similar, and I am almost 100% positive that this is the same issue:
http://android.stackexchange.com/a/108437

 

[gligeti]

Good news!

It seems that I got my GPS working again. Apparently the upgrade was not the root cause for it to start working, only a side effect of the upgrade (that it cleared all traces of AGPS data cached in the system) that made it function robustly.

It seems that under some conditions (maybe on this chipset/software/apps whatever combintation) the AGPS reset doesn't actually reset the GPS data (neither from GPS Status and toolbox, not GPS test) even with Airplane mode on. I initially thought that my AGPS is not functioning as I didn't see any difference after doing a reset, it immediately came back with some satellites seen (even with the Airplane mode, so it was certainly not redownloading it). But in fact it seems that it actually gets cached in a way that the resets are not clearing it completely while the GPS is turned on. It seems that the only way to reset it fully and do a cold start is to reset it while the GPS is turned off (!). So, if I turn off GPS, do a reset, I also waited 20-30 sec and did a reset again, waited again, then turned it back on, it was now clearly doing a cold start and slowly started to pick up the satellites. I otherwise then followed your procedure, and presto, my GPS is solid again!

Now what I actually did that seemed to fix it (probably the above augmented reset procedure is the key) was that I had the phone in the car where I use it for navigation, started Waze, pulled up GPS status & toolbox (which shows its little icon in the status bar), and did the augmented procedure of #7 and #8, so in Airplane mode AND GPS off, I did an AGPS reset, then waited ~20 sec, AGPS reset again, wait 20 sec again (probably not needed, should need to test), then turned GPS back on -- NOW I could see it cold start and took minutes to pick up first few satellites enough to get the location, then little more to actually load the full sat data and show the 19-20 sats visible. I've never seen it pick up the position that slow, so clearly I was not able to fully reset the AGPS data.

After that, I seem to have stability back (the first obvious sign is that Waze reports close to correct speed, while before it was anywhere between close to the real speed and way, way lower, like reporting 24 km/h when in fact I was driving 50 km/h) and then no drop of GPS signal. I will test more to see how accurate it will remain.

My theory is that if the GPS module gets a downloaded AGPS dataset BEFORE it ever does a fix on it s own, it will be instable (in line with your procedure, you want to force a "clean" fix before applying AGPS data). When I did my spring update, as the upgrade did a full reset, I probably happened to use the GPS before the toolbox scheduled the download and refresh the AGPS data, while in the Aug upgrade it got AGPS before an unaided fix.

So, you may want to add that optionally you want to try the reset with the GPS turned off as at least in my environment that is the only way to fully reset it.

 

[Terry Barnaby]

Just for anyone who sees this thread in a search for Samsung S5 GPS issues (as I did). I have seen two phones where the GPS has gone bad. These have had low level GPS signals when a GPS test application is used and GPS worked to a degree but slow to lock and in-accurate (> 200m). In both of these phones it was due to damage to the GPS antenna. It looks like this is outside of the water seals of this phone ... If you replace the "middle frame" of the phone (about £4) this has the chrome plastic edge and buttons but also contains the GPS and all other antennas and fixes the problem. You do have to dismantle the phone to do this including un-glueing the LCD panel with heat, but it is reasonably easy for those that can DIY if you are careful.

 

[Kiriakos_GR]

My S5 never had any GPS issue, even so by testing Manage A-GPS state > Reset this seems cleared GPS receiver cache and now it locks much faster.
Specific app sucks in my eyes regarding user inter-phase, I have firewall at my phone, this app never send or download anything from my phone, therefore I am now convinced that temporarily improvement which I am now witness this is because of cleared GPS receiver cache.

My phone this came from Switzerland to Greece before 2.5 years ago, I am now assuming that is possible GPS receiver cache this to kept in storage identification of satellites serving north countries.
Therefore now that GPS receiver cache this is cleaned, now there is stored information's only of the satellites available in my location, and somewhat this helps as speed improvement.