Develop Bugs

WCDMA / GSM auto problem

Hello Guys,
I'm experiencing a problem with my Froyo Desire for probably a week now.
The thing is that in certain areas my Phone can not receive calls / sms or such. In other words "GSM services" dont work. 3g though works fine (stable, strong and fast connection) My Provider is T-Mobile.
After quite a lot of testing I was able to isolate the error:
When WCDMA / GSM is chosen by the phone automatically it seems to me as if it didnt switch "back" to register with my provider via GSM when i want to make a call or if someone wants to call me.
When i switch to "GSM only" manually everything works fine but i have no 3g of course.
I also experience this problem only in certain areas. I live in an area where there is really strong HSDPA available (up to 7mbit\s). When i go to other places of my city i still get HSDPA (not as strong) but calls / sms still work.
The last paragraph may be of no importance, i don know.. probably it helps..
I have googled quite much about this problem and also found a few persons experiencing the same issue but nobody was able to come up with a solution.
I would be very thankful if someone could try to figure this out.
schnip

push______

Hi Guys,
... exactly the same problem here!
- same device
- t-mobile germany
- problem exists only in specific cells
ideas or solutions welcome
LordKnut.

gsm only Desire?
I'm having a nightmare with 3g 2g connectivity on my Desire on the three network whilst at home. If I could manually select gsm only this would be fine as I could still call and text and use wi-fi. Unfortunately my options are gsm/wcdpa (or whatever) auto or the 3g only.
can someone please advise if it is possible to select gsm only and if so, how?
many thanks

Can someone please advise me how if possible, to set the desire to gsm only?

VKeane said:
Can someone please advise me how if possible, to set the desire to gsm only?
Click to expand...
Click to collapse
Wireless and network-Mobile network- should be here somewhere.

Thanks, but there is no option for gsm only. It's wcdma only or gsm/wcdma auto. there has to be a way around this.

Similar problem, different version
I've experienced similar problem.
In some area, I can get steady grps signal when I switched GSM only on; but when I switched WCDMA/GSM on, I could get no data connection at all.
I'm using China Unicom's mobile service.

Solution
Hi there,
I've the same issue and I fix it allowing the option GSM/WCDMA Auto in the configuration menu.
Then enter the following code *#*#4636#*#*, select "phone Information" and set preferred network type, set "GSM car (PRL)".
Sorry about my bad english.

Can't get LTE + Network to work

Hey guys! I recently bought a G3. It's a Korean Variant LG-F400L from U+. My problem with this phone is that when set to "Global" mode (GSM/WCDMA/LTE) it connects to LTE but says "Not in Service Area" whenever I try to make a call so I don't get the normal call and text services but when I set my network mode to (WCDMA Only) I get the call and text service but no LTE only 3G. So maybe Global mode prioritizes GSM? I don't know.
If I do LTE only mode, I can receive texts I believe but I can't make phone calls. I know it is not a problem with my network, as I have a Galaxy Note 3 and LTE + Calls work fine on my Note 3. Yet this G3 will only do one or the other. There is no option from WCDMA + LTE only.
IF anyone has any ideas, I would love to hear it. I'm also wondering if changing the rom would help this issue.
I should also mention that I am on another provider (SK Telecom) while my phone is a unlocked U+ phone!

Metsuna said:
Hey guys! I recently bought a G3. It's a Korean Variant LG-F400L from U+. My problem with this phone is that when set to "Global" mode (GSM/WCDMA/LTE) it connects to LTE but says "Not in Service Area" whenever I try to make a call so I don't get the normal call and text services but when I set my network mode to (WCDMA Only) I get the call and text service but no LTE only 3G. So maybe Global mode prioritizes GSM? I don't know.
If I do LTE only mode, I can receive texts I believe but I can't make phone calls. I know it is not a problem with my network, as I have a Galaxy Note 3 and LTE + Calls work fine on my Note 3. Yet this G3 will only do one or the other. There is no option from WCDMA + LTE only.
IF anyone has any ideas, I would love to hear it. I'm also wondering if changing the rom would help this issue.
I should also mention that I am on another provider (SK Telecom) while my phone is a unlocked U+ phone!
Click to expand...
Click to collapse
Hi! I guess you're in Korea? Have you tried another sim card? Is this a new phone or did you purchase it second hand?
EDIT : It sounds like a network problem.. The phone hasn't been registered correctly.

Did you make sure you have the right APN settings?

So I actually changed my mobile provider to u+ because I was off contract and my phone was able to get VoLte and LTE. So maybe the issue was the phone defaulting to VoLte? I have no idea how to turn it off on this F400L model. I've tried most of the methods I think. Any ideas how to turn it off? Either way I guess it's a little bit solved now that I can call again.

I am having the same problem
Hello Metsuna
Can you tell me how you solved the problem, I am having the same problem and cant connect to internet. Can;t make or receive any calls.
Thanks

Problem with using on ATT

Hey So I'm having some issues after sim unlocking phone;
I sim unlocked my phone and then flashed it back using odin to stock and still having issues.
Issues:
-While it says LTE the device does not seem to be getting actual LTE as doing a speed test revealed about 2-3 mbps
-When calling someone, they can rarely hear me
-When someone calls me I can't answer the call, I swipe to answer and the phone hangs then shows the call screen again and I try to answer the second time it usually disconnects the call
-When I am able to answer the call no audio and the call automatically hangs up after about 5 seconds
I know that the microphones are good as I can make calls using FB Messenger and don't have any issue since it's using the data.
Steps I have done:
-Flashed back to stock
-Factory Reset after Flash
-Manually set network to: AT&T
-Disabled WiFi calling
-Set network to 2g/3g to see if the LTE was causing the issue
....none of this seems to have made any difference in the issue.
Any recommendations, suggestions, in-sight would be great! Wondering if I should just sell this and get an ATT phone or if I can fix the issue.
I had read in some thread that someone had to get a new sim but from what I remember of the thread they weren't seeing anything data or the ability to select a operator. The phone the SIM originally came from was a iPhone 5C if that makes any difference.

This worked for me:
1) Use an "activity launcher" app to launch Device Info com.android.settings.radioinfo (there is one by that name in the Play Store that I use; Alternatively, Nova Launcher has a handy widget function to launch activities.)
2) Once Device Info/Radio Info is open, there is a drop down menu mid-way down the page that allows you to select various combinations. The default is intended for TMOBILE networks.
For AT&T, select "LTE/GSM (Auto)"
3) Reboot the phone
While the Radio Info settings updated to "LTE/GSM (Auto)" did immediately resolve the mobile data issues on AT&T for me, checking your active APN (that's it's using the AT&T Nextgen APN) might be worthwhile as well.

The program I actually tried to do this with was "4G LTE Switcher"; I had used it back with my XT912(Droid Razr Maxx) because it had lots of problems with custom roms and not connecting to the network and I tried those methods:
1. Turn on airplane mode and turn back on to establish connection after power on
2. Turn on airplane mode, power cycle
3. 4g Switch/ Turn data to CDMA only and then back to LTE (when was on verizon)
Things I've noticed:
1. If I'm on wifi the call audio never works even though I have disabled wifi calling
2. If I'm on LTE the call never works and for some reason like the phone doesn't want to switch over to HSPA
3. If I'm on HSPA+ it works more often on incoming calls than outgoing
I got a new sim card from ATT and had them add the IMEI into the system but didn't help at all.
Nougat should be out soon and hoping that I can get it fixed, going to try some rom flashing and CSC flashing to see if I can get a result out of it

I got my s6 edge plus in a trade, i was able to get it unlocked finally and was wondering if there is an unbranded rom that can be installed on the tmobile variant ? I have at&t as well.

unable to receive calls on LTE network

hi guys,
I'm having issues receiving calls when my preferred network is on LTE/3G/2G but I'm able to use data and receive SMS.
steps made trying to narrow down the issue:
• switching to 2G only network type allows me to receive calls
• swtiching to LTE/3G did nothing to resolve the issue
• went to phone info using *#*#4636#*#* and changing to Global auto prl allows me to receive calls but only if the voice network type is UMTS and data network type is HSPA switches from LTE.
• had my gf call me on LTE while looking in phone info (using *#*#4636#*#*), I can see network types changing from LTE to UMTS and HSPA respectively but still unable to receive calls though on my gf's phone is ringing on her end.
hope you guys could help!
*on android 8.1 btw

I had this exact problem, I restarted the phone and it fixed the issue. I also disabled and re-enabled WiFi calling. Let me know if it worked for you.

What network are you using?

thanks for the reply guys, called raser support and turned out to be my phone's modem has an issue. sending it for RMA tomorrow..

No phones calls in France

Hello, I bought an S7A on eBay. I unlocked it with the GSM unlock code provided. Everything works fine, except ... I can't make or receive calls. When I make a call, no ringing tone, and it hangs up 20 seconds later. When someone calls me, the same, then they come across my answering machine.
I'm on the latest version of Oero available, no root or whatever. From what I saw (on GSMArena), the phone uses compatible frequencies in France.
I am at carrier Bouygues Teelcom.
You have any ideas ? Thank you !
PS: I translate from French, please be indulgent!

Same problem, this phone does not work in China

Since then I have understood the real problem: the phone cannot switch from the 4G network to the 2G network for calls on its own.
I don't know how I did it, but now I can make calls without any problem, but switching to 2G is very long (15 s).
I specify that it is impossible to use VoLTE to circumvent this problem.
For receiving calls, the phone does not switch to 2G and the incoming call still fails.
But I can force the 2G network (With the Samsung Band Selection app). And there, incoming calls work, but we only have 2G to surf.
When connected to WIFI, the phone automatically forces the mobile network to 2G, so incoming calls work without the application mentioned before.