Develop Bugs

[Q] 3g/1x Data blocks incoming calls PLEASE HELP!

If I'm posting in wrong spot, sorry and let me know where to post.
I'm seeking help in getting this resolved in hopes that my last resort won't be to have to change phone number. Ima try to make it short. While my data is running (3g or 1x) incoming calls don't go through.
Story begins........
Bought used samsung epic 4g (clean esn) and had it flashed by mailing it to some guy in craigslist. Received it back with donor phone. I had metro pcs, and had my number ported to boostmobile to have the flash done. As time passed, I noticed data was slow. After research, I come to find out it was flashed with wrong-non 3g phone. I then noticed I kept missing calls. Did a test call and found out that no calls go through while I'm on web/youtube/pandora/anything that relates to data connection.
Things I've tried
1. Reflash phone with another donor phone sanyo incognito. (Now I get 3g but still no incoming calls while using data)
2. Changed roms, tried about 6 different roms.
3. Changed prl 3 times.
4. Called customer service to refresh signal/phone number. (3 times)
5. Reflashed phone AGAIN using another donor phone.
STILL no go!
Ive researched but got nowhere. I'm hoping someone can give any type of advice.
Note: I havnt flashed the phone myself, always take it to a spot to get done. Had my wifes number also ported from metro pcs and flashed same type of phone, epic 4g but she doesn't have same issue. Her phone is flawless!
Please help me, I've had same phone since the first flash, my epic 4g. Another words, SAME MODEM. Can modem be the problem? Could my line be crossed, radio? Any comments, suggestions, questions for me, ANYTHING PLEASE!
Thanks to all in advanced!

Network Connection Issue

I've been using an S4 for about 2 weeks now, no problem. Last night I realized a text I sent never went through, and today my lock screen says "No Service" or "Searching" (despite the device showing full signal). I can't send/receive calls or texts, and I don't use a data connection. This SIM is also new (~2 weeks), and the device is neither rooted nor running a custom ROM. I've tried everything I could think of, like:
reboot
pull battery and SIM
confirmed APN settings on t-mobile site
tried alternate, non-"LTE" APN (epc tmobile com)
tried every network mode setting (GSM, GSM/WCDMA, etc.)
reset APN to default
turned on mobile data connection
manually scanned for networks (wouldn't connect to AT&T or T-mo)
select network automatically (wouldn't connect)
complete factory reset
I tried my SIM in another T-mo phone and it works; tried a different SIM in my S4 and it doesn't work. All other T-mo phones in my household are working fine. My S4 is definitely the problem here, but I don't see how the radio would just stop working after 2 weeks.
Has anyone else experienced/seen this? I never have, and it's driving me up a wall. I'm going to try my local T-mo store tomorrow, but I was hoping to fix it before then. Any help is greatly appreciated.
EDIT: I purchased the phone new on ebay. For a minute I thought the seller might have reported the phone stolen, but I checked the IMEI and it's clean.

Ive experience this but my service came back in about 25 minutes I did reset reboot battery pull sim pull it just came back on its own
Unrooted Samsung Galaxy S4 Up and Running
Rooted Mytouch 4G Slide retired
Rooted T-Mobile Sidekick Touch Obliterated
Rooted Mytouch 3G Slide Lost
Rooted T-Mobile G1 Dead

So I finally got to T-mobile today. Unfortunately, my hunch was right: the IMEI is blacklisted. Their in-house system must be more up to date than their web IMEI checker.
Time to solve this issue elsewhere.

Can not connect to 4G/3G.

Hello there, I'm in need of your help again.
My SGH-M919 has a problem, it cannot connect to 3G/LTE (Not even EDGE). My carrier uses the 850 mHz band for GSM and 1900 mHz for UMTS, so the phone should be able to use them. The thing is, it doesn't. It only connects to GPRS and the signal is very erratic and weak (Usually 2-3 bars). Sometimes I get SMSs from my carrier saying that I missed like 5 calls when my phone never rang once. I live in a zone with good 3G coverage, so it's not the signal.
I'm currently rooted on Android 4.4.4 (NH7). I already tried selecting "1900 WCDMA" in the *#2263# service menu but that only causes the phone to lose all the signal (And it's a problem to change it back, without signal the service menu doesn't work and I cannot change the Network Mode in Settings).
I've tried to select "WCDMA only" mode before, but my signal just goes to zero (The circle with the slash) before changing back to "LTE/WCDMA/GSM (Auto connect)" automatically.
I also cannot use the Network Operators option. Using "Search now" makes it search for a few seconds before showing the message "Error while searching for networks". The "Select automatically" one shows the message "Unable to connect. Try later" and then connects back to my carrier (Movistar)
My APNs are configured (They did it themselves when I inserted the SIM, but I've configured them manually before). The SIM card works, I tried it in another phone and it got 3G immediately, I also tried another SIM card on the GS4, but the result was the same. Someone told me to upgrade to the latest firmware (NK2) while someone else told me to flash the MDL modem. (Is that even possible? I read something about KNOX blocking all downgrades after 4.3).
Since I couldn't find any direct solution to the problem, I'm recurring to you.
Thanks.
P.S: I didn't change the LTE Band Preference option in the Service Menu because the last time someone messed with it, my IMEI/Baseband went completely nuts, I thought the EFS got corrupted, but they magically appeared everytime I enabled the Airplane Mode (So I was able to select Automatic in the ServiceMenu and they got fixed). Also, I don't live in a LTE area although once during a very strong thunderstorm, I got 4G for a few minutes before going back to G).

*bump*
Any ideas?

Did you put a check mark in data roaming?

Shortbus-Driver said:
Did you put a check mark in data roaming?
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Click to collapse
I've tried with and without it, it doesn't make a difference anyway.

Does it show you have an ìmei # other than all zeros?
Don't post it just a yes or no.

Shortbus-Driver said:
Does it show you have an ìmei # other than all zeros?
Don't post it just a yes or no.
Click to expand...
Click to collapse
My IMEI is fine, the phone connects to the carrier network but it stays on GPRS (and the signal is always dropping)

Update to full NK2 firmware and see if that will fix it

serio22 said:
Update to full NK2 firmware and see if that will fix it
Click to expand...
Click to collapse
I'll try that later. Will I have to re-root and re-install TWRP after flashing NK2?

I have a similar problem with my M919 on the Tmobile network. Using the *#2263# menu I can not get mine to work on WCDMA (4G) either. I can chose GSM /LTE only and my phone works normally but no 4G signal. If I chose WCDMA I get no signal. I can see it trying to connect and immediately dropping the signal. If I choose any option with WCDMA included it has erratic signal and will lose the signal most of the time when I try to make a call. So basically I have the choices of GSM only or GSM/LTE only. Before I discovered the secret menu I was stuck with GSM only in the phone's settings. This has been going on for months. Tmobile changed my SIM card and it didn't help. I've rooted and unrooted my phone (using autoroot) and even tried different modems (even worse signals) and now am back to stock rooted NK2 firmware and modem. I have given up and decided to get another phone (not an S4). My wife's S3 gets great 4G signals in the same location by the way. I wonder if anyone knows why our phones can't use 4G. I am beginning to think it's a hardware problem but I'm way out of warranty on mine.

Can't dial or send/receive SMS

Hi there. Recently my Nexus 5X has something wrong with its communication function.
I am using CM13 nightly builds with ElementalX kernel on 4GLTE network. And everything works fine except:
When making calls, it ends up with "Network not available". However, the signal bar is full. Also, it is unable to send or receive any text message.
I have already tried:
1. Flash the latest factory image from Google(mtc19v). And it worked for a while then the issue recurred.
2. Dial *#*#4636#*#* and switch to "CDMA only" but it failed to make it, automatically rolled back to LTE mode.
3. Tried CM13 snapshot and other nightly builds, and still got the problem.
Does anyone have any advice? Thanks.

Cijophxon said:
Hi there. Recently my Nexus 5X has something wrong with its communication function.
I am using CM13 nightly builds with ElementalX kernel on 4GLTE network. And everything works fine except:
When making calls, it ends up with "Network not available". However, the signal bar is full. Also, it is unable to send or receive any text message.
I have already tried:
1. Flash the latest factory image from Google(mtc19v). And it worked for a while then the issue recurred.
2. Dial *#*#4636#*#* and switch to "CDMA only" but it failed to make it, automatically rolled back to LTE mode.
3. Tried CM13 snapshot and other nightly builds, and still got the problem.
Does anyone have any advice? Thanks.
Click to expand...
Click to collapse
Try getting a new simcard from your carrier.

Darke5tShad0w said:
Try getting a new simcard from your carrier.
Click to expand...
Click to collapse
Thanks for reply. I will try ASAP.

OK. I have fixed it. This is the MOST weird and tricky problem I have ever met since I knew Android phones.
First there are some key concepts:
From the "*#*#4636#*#*" (Testing) menu -> Phone Information, we notice IMEI, Phone number, and Current Network. In my case I couldn't make phone calls or send/receive text messages, I got my IMEI and Current Network NORMAL, but I got NOTHING for my Phone number section, which means my phone turned into something without a number! So how can it be discovered by the mobile base stations?
Furthermore, scrolling down there are another 3 indicators: GSM service and GPRS service and Network type. In my case the GSM service was "Emergency calls only"(However there is someone on the Androidcentral Forum said his Nexus 4 under the same circumstance can't even dial 911), and I doubt that. The GSM service was COMPLETELY offline. On the other hand, since my data service ran smoothly thus the GPRS service is always "connected". The Network type is "LTE". I have tried many times to change it to the CDMA or GSM ones, like "eHRPD", "1xRTT", "EDGE" or sth else but few succeeded. Once succeeded, I can normally voice or text, yet on the outdated network.
Then how I fixed this:
I googled "Mobile network not available" and got many results about the Samsung phones. Then googled "mobile network not available nexus" and found this one "Mobile Network Not Available" on Nexus 4 T-Mobile which perfectly matches my case. Finally I thought it had something to do with my network provider and my phone should not be blamed. I just tried another SIM card from another carrier, which worked perfectly on LTE network with voice and text. When I opened the *#*#4636#*#* menu and tried to change "preferred network", the phone also worked smoothly no matter WCDMA only/GSM only/LTE only. I put back my bad SIM card and the voice and text came back!??? I was extremely confused. That is to say, still there was a problem on my phone. By inserting another SIM it just did something like refreshing the stucked radio module??? I wondered. After this simple trick I got my voice and text back though, the "Current network" became "Roaming Indicator Off".... Maybe the next time.

LG G8 Amazon edition on Sprint, can't make/receive phone calls/texts, but HAVE Data

Got the LG G8 unlocked Amazon Alexa edition last August (2019). I use it with Sprint. I love the phone and it worked great, until a month ago.
All of a sudden, I can't make or receive phone calls or text messages, but I DO still connect to the Sprint cell service (I have bars) and I DO have working 4G LTE Data. Literally, one day it worked and the next day it didn't. I hadn't powered cycled the phone or anything between it worked and when it suddenly didn't. It just stopped working.
When I try to call out, the dialer gives me an "Out of service area" message, even though I'm within my service area. When someone tries to call me, it goes straight to voice mail as if my phone is turned off, except that my phone is turned on. When I try to send a text, it sits at "sending" indefinitely and never sends. When someone sends me a text, I simply never receive it.
Sprint, I do firmly believe, has done everything they can to troubleshoot it and proven it's not a network issue. Several different kinds of resets, including a factory reset. I was able to reactivate an older LG V20 on my account and it works just fine.
The phone is still under warranty with LG, and I was able to send it in for repair at no cost, but they did not find anything wrong with the hardware. They did do a software update of some sort, but that did not resolve the issue.
So now I'm essentially stuck between both Sprint and LG saying it's the other's issue. First unlocked phone I've ever bought and it bites me in the butt.
Any other ideas for troubleshooting either on the phone itself (beyond all the standard stuff which I've already done; I mean, if a Factory Reset doesn't help...), or with Sprint?
Thank you!

I had the same problem with Amazon variant. I used an app called Hidden Settings Muiu and went to "Phone Info" then switch the Preferred Network Type to LTE only leave it on there until it says LTE on data and no network on Voice then switch to LTE/CDMA and it get 1xRTT. Ive tried tweaking settings and everythingelse but no luck that seems to be 100% effective but anytime you **** with your network or restart you'll have to do that.
Edit: Do Global(PRL) then LTE only then to LTE/CDMA. Otherwise itll stay on EvDo for data not LTE.

Cinomed541 said:
I had the same problem with Amazon variant. I used an app called Hidden Settings Muiu and went to "Phone Info" then switch the Preferred Network Type to LTE only leave it on there until it says LTE on data and no network on Voice then switch to LTE/CDMA and it get 1xRTT. Ive tried tweaking settings and everythingelse but no luck that seems to be 100% effective but anytime you **** with your network or restart you'll have to do that.
Edit: Do Global(PRL) then LTE only then to LTE/CDMA. Otherwise itll stay on EvDo for data not LTE.
Click to expand...
Click to collapse
##3282#, apn settings, view, 3 buttons top right, reset to default. Works for most people, may or may not work for you

antintin said:
##3282#, apn settings, view, 3 buttons top right, reset to default. Works for most people, may or may not work for you
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Click to collapse
Did try that and gives me data but no cell service. Thank you though

Had same problem from a newbie...
I used ##873283# with dial key pad. It took a few times but finally worked. As soon as you power off or restart your phone, your back to where you started.
I bought mine from bestbuy 1 1/2 yrs ago. They are having lg send me a new one...
Lg v8 thinq This is the model I had* LM-G820QM.
Good luck.
Had my settings on LTE/cdma with roaming turned off.