[AT&T Samsung Galaxy Note II] kodiak0385:
My problem in short: Cell signal loss

More info: It started in late November pretty suddenly. One day I was no longer getting the 2-3 bars of 4G reception I had always been getting at work, at my desk. I would either get the ‘No Service’ symbol or 1-2 bars with no E/G/4G/LTE symbol next to the bars, which (I believe) signifies I’m registered to the network and communicating with it. For the first week or two I thought maybe they were working on the tower(s) in the area and I just needed to wait it out. After 2 weeks I started searching the XDA forums for people with similar problems but didn’t see anyone with symptoms exactly like mine. I did go get a new SIM Card form an AT&T store and called CS to activate it but that changed nothing. So I’ll put all my symptoms out and hopefully one of you glorious devs can layout my best course of action House M.D. style.

Device: Samsung Galaxy Note II (SGH-i317)

Network: AT&T

Purchase Date: Nov 18, 2012 (out of warranty)

Baseband ver: I317UCUBMK6

Kernel ver: 3.0.31-2048209, se.infra@SEP-117 #1, Tue Nov 19 16:46:45 KST 2013

Build Number: JSS15J.I317UCUBMK6

SE for Android status: Enforcing, SEPF_SAMSUNG-SGH-I317_4.3_0010

IMEI/IMEISV: Both numbers are whole and match the inside sticker.

OS History: Completely stock until early Dec 2013 when I was on 4.1.2 and rooted using Odin/CWM Recovery about 2 weeks after my problems started b/c I was gonna try some of the things I read on XDA (SELinux to Passive, RIF/Modem, Repartition, ect)but before I had the chance I saw the 4.3 OTA Update was out and thought “This should at least reflash/update my modem and hopefully fix it”. NOPE, I lost root with 4.3. So now I’m on 4.3 Stock OTA and the only reason I haven’t re-rooted is because I know I’ll trip KNOX which even though I’m out of warranty already, whining to AT&T that their 4.3OTA screwed up my phone maybe still an option if any of you guys suggest it as my best option (but they could more easily refute my claim if I trip KNOX). I’ve also tried at least 5 different APN settings which made little or no difference.

Additional Symptoms:

-	The problem is more a “degradation” (worsening) of the signal than a complete loss, meaning in areas where my signal was previously ‘weak’ I now get the ‘no service’ symbol OR 1-2 bars without Network Registration which still gives me the “Emergency Calls Only” message. But in areas where I usually had near perfect reception (5 bars 4GLTE) I now get usually 1-2 bars less.

-	There are times at work (usually when I’m one of the last ones on the floor) when my signal will fluctuate to a 3-4 bar 4G connection for a few minutes and then back down to ‘No Service’.(Which indicated to me that it isn’t a bad antenna since a good reception IS possible and the problem is likely software related.) Also my cubicle mate a has an AT&T iPhone 5 that consistently gets 3 bars of 4G and his phone is 5ft away from mine.

-	If I go to About Device>Status and watch my ‘Signal Strength’ without moving my phone it will fluctuate from -95dBm 7asu to -113dBm 0 asu.

-	I’ve made a successful call(although it took forever to connect the call and start ringing, as if it were struggling) while my signal was -105dBm and 5asu with “Mobile Network Type: Unknown” “Service State: In Service” “Mobile Network State: Disconnected” with one bar of service but w/o any type of connection type designator next to the bars(E/G/4G/etc).

-	Sometimes when I leave work or someplace that I have had poor/no connection and get closer to a cell tower, my signal bars will go as high as 5 bars but my phone still won’t make a call or show a connection type designator (4G/LTE/Etc.) next to the bars and gives me the “Emergency Calls Only” message until I either restart the phone or wait.

-	When I’m at home and connected to my WiFi my phone seems to make no attempt to stay connected to the Cell Network even though I have 4-5 bars of service it shows no type of 4G/LTE connection unless I turn off WiFi.

-	I should say that I use an app that takes frequent screenshots which are stored on the phone’s storage until I erase them. (up to 300-500 @ about 1MB each) I’ve read pushing/pulling lots of data to/from your device’s storage can cause partition problems and I imagine creating/deleting large amounts of data as I’m doing could have the same effect.

-	Also if I’m sent a voicemail while without service I still won’t immediately get it when I my phone regains a decent connection and have gotten voicemails up to 2 hrs after they were left.

From what I’ve read on the forums so far I have seen the following options but would like a recommendation on what to do and what order to do them in. (I have no worries about tripping KNOX if it means getting the phones cell reception back to normal. I’ve had the phone >1yr anyway.)

-	Root (which method?)

-	Unlock bootloader

-	RIF (Radio/Modem Reflash?)

-	Re-partition the device storage

-	Set SELinux to Passive

-	Enable AWS (T-mobile 3g/4g)

-	Install Custom ROM (suggestions?)

-	EFS file something or other

Thanks in advance and I’ve included a few screenshots of the About Device>Status screen.