[Galaxy S 4 Q&A, Help & Troubleshooting] Chikara71:
Hi all,

Regular reader but hardly ever post!

I have a Galaxy S4 (GT-I9505) - with Android 4.4.2. Unrooted.

Purchased and used in Singapore on the Starhub network since around October 2013. Everything was working fine until approx Feb or March when the latest Android version, 4.4.2 got rolled out.

Ever since then I am experiencing regular disconnections from the network. But the phone does not re-connect back to the network again, the only fix is to restart the phone.

These disconnections are often once or twice a day, and are very frustrating because if I don't notice it, I may be off the network for hours before noticing it - and are therefore missing out on calls emails etc etc.

This only happened after the Android 4.4.2 got rolled out, so I am pretty confident this is the cause of the problem.

What I tried myself to fix:

- restore APN's back to default state

- Factory reset (both via settings, and via boot screen)

What I have been able to narrow down troubleshooting, is:

- Disconnects seem to only happen when Network Mode is "LTE/WCDMA/GSM (auto connect)"

- If I use network mode "WCDMA/GSM (auto connect)" the disconnections have not happened (yet!)

- When the disconnection does happen in the first mode, I cannot manually change the network mode. The radio buttons are greyed out, and if I try to select "WCDMA/GSM auto connect" the request times out (I forget the exact message - it does respond to the tap but then nothing happens)

So it seems to me this is some sort of software bug/fault introduced with Android 4.4.2 that affects 4G connections.

After that, I have taken it to Samsung for warranty service. I have now had 4 visits to them and they have not been able to fix it yet. This is what they have done so far:

- First visit - factory reset (despite telling them I already did that) - did not fix

- Second visit - checked hardware and replaced mainboard. Did not fix.

- Third visit - checked hardware again and factory reset again. Did not fix.

- Fourth visit - who knows. I think same as visit three but done via a Service Manager instead of staff, Did not fix.

When I first called them back in Feb or March, they said it was a "known Issue' and sugegsted to "wait for a patch". However since visiting them, they said the known issue was only with Note 3's (not with S4's) and replacing the mainboard on the Note 3's fixed the problem. In my case replacing the mainboard - twice - has not fixed it.

I'm getting very annoyed with Samsung who seem to just be trying the same thing each time and are not fixing it. Staying in 3G only mode is a workaround but not an acceptable solution.

Now they've asked me to take if back again - for a 5th time.

Beginning to wish I had never bought the S4, or at least never got Android 4.4.2.

So I thought I would turn to here for help instead, I think you guys and gals probably know more than the Samsung service staff!

Any suggestions?

By the way, I don't run any memory/battery saver apps. I do run one data usage monitoring app that I thought perhaps was conflicting, so I tried not installing it after one of the resets, but the problem continued.