4g with small cross in the bottom - Xiaomi Mi A1 Questions & Answers

Ever since the oreo update, my phone has a tendency to show the reception icon with a small cross at the bottom after going in and out of wifi range.
So there is effectively no data coming in. After investigating further i see in the phone info dialor code *#*#4636#*#* that its frequency went to TD-SCDMA.
Weirdly enough i live in Europe and it should go for LTE, there is no TD-SCDMA here.
Everytime i have to change it to Global and change the data renewal frequency to immediate to get no data problem resolved, but then i can't make or receive calls anymore.
Only a reboot gets it fixed. Is there anybody else having this issue or found a solid way to fix this? Before the oreo update this was absolutely no issue.
I already tried factory resetting it, but that didn't help at all.
Also, my phone isn't rooted and havn't tinkered with it yet.
Any ideas?

Don't change it to LTE only. Try other options, for example LTE/TD-SCDMA/GSM. Set your preference to anything else you find useful, but not LTE only.

Related

Wow, this is ridiculous and why is this happening?

Please help:
I'm on CM9 19 6 nightly. Using Semaphore kernel without any modifications to the scripts.
The problem: My signal keeps on going out at regular intervals.
I've used XXJVU, DDJV5, XXJVT, KF1(Nexus modem for ICS) and various more. I stay on the modems for a week and then change to another one. The latest one is DDJV5 which I have been using since the past 2 weeks.
Tried all of the modems I could lay my hands on. Nothing works.
But the moment I come to work, the signal keeps fluctuating over the day. Sometimes it would be out for 10-15 minutes. When it's back, it would get back to giving -65 .. -71 dBm. It would stay like that for a few minutes and then it would be gone again for another 10-15 minutes or so.
It has turned into an OCD where I keep checking my signal.
This does not happen when I'm back home and then I'm back to getting good signal.
Yes, this looks to you like a locational issue. I thought so too. BUT, how did I get so good signal till a week back at work?
Question: What could have made this mess to my signal reception? How can I solve this?
No, all my syncs are OFF. I keep my 3G turned off and only use it once an hour or so for a few minutes. I don't use any signal consuming apps.
Also, sometimes the 3G would work even without the signal.
Another thing, sometimes there's a (x) sign at the signal bar thing and sometimes there is no (x) without bars.
As a cure for the OCD, I've taken an off from work today just to get some rest from checking my signal every now and then. And maybe find a solution.
I'm on Vodafone India.
Indians, I am on Vodafone India in Pune, Hinjewadi Information Technology park. Maybe Pune guys can help me out too?
maybe the phone changes the network mode.. 2g 3g or i dont know , try to put in in 2g only mode , or gsm only mode.
When the signal bar shows with a "x" it means the network is not available...go to settings and change the Network mode to "GSM Only". It will solve the fluctuating issue but network speed will be limited to 2G only.
Sent from my GT-i9100 equipped with Grenade Launcher and Remote Explosives
Thanks, let me try it out.
Where is the network changing option to GSM only in ICS?
Okay, I guess it's the 2G mode.
DD-Ripper said:
When the signal bar shows with a "x" it means the network is not available...go to settings and change the Network mode to "GSM Only". It will solve the fluctuating issue but network speed will be limited to 2G only.
Sent from my GT-i9100 equipped with Grenade Launcher and Remote Explosives
Click to expand...
Click to collapse
Is going to 2G mode my ONLY option?
How can I fix this and get back to using 3G?
Update:
Changing to 2G mode fixed the problem. BUT...
I have a few questions now:
I want to use 3G but at the same time I don't want the signal to fluctuate between 2G and 3G—want to get constant 3G connectivity without signal fluctuations. Is there any way I can fix that?
I remember reading somewhere that going to recovery and changing permission helps this.
Anyone knows how to change the permissions so the signal fluctuations stop?
I have done a lot of reading on XDA but I haven't noticed an issue like this.
CM9 guys, anything please...
TVwithParents said:
Update:
Changing to 2G mode fixed the problem. BUT...
I have a few questions now:
I want to use 3G but at the same time I don't want the signal to fluctuate between 2G and 3G—want to get constant 3G connectivity without signal fluctuations. Is there any way I can fix that?
I remember reading somewhere that going to recovery and changing permission helps this.
Anyone knows how to change the permissions so the signal fluctuations stop?
I have done a lot of reading on XDA but I haven't noticed an issue like this.
CM9 guys, anything please...
Click to expand...
Click to collapse
I have the same issue mate...using 2G is the only option to get signal without any problem.
The problem doesnot lies on your phone but the problem is with the operator. The area where you live hardly 3G signal reaches there (same problem with me).
You got two options to fix this issue:
1. Change your Network Operator
Or
2. Settle to another location where 3G signal is fully available
Sent from my GT-i9100 equipped with Grenade Launcher and Remote Explosives
Both the options look impossible for me at the moment.
I will start living with the hope that the operator brings us some decent 3G signal here.
Thanks a lot anyways. It was helpful. Hope others facing the issue can learn from this thread. :good:
TVwithParents said:
Both the options look impossible for me at the moment.
I will start living with the hope that the operator brings us some decent 3G signal here.
Thanks a lot anyways. It was helpful. Hope others facing the issue can learn from this thread. :good:
Click to expand...
Click to collapse
Complain to your provider, very loud!
:gooditto the same problem occured to me on Vodafone (Chennai) tried all modems listed above nothing worked ...Used to lose signals all the time with 2g data on especially at my workplace intermittently for 3-4 months ever since I upgraded to ICS..Sometimes used to lose signal even if data was off..multiple reboots/restarts gave no solution ..issue persisted across all the 15+ roms i might have flashed over the past 6 months..
Finally fed up I ported the number to AIrtel..everything works like a charm on JV9 I must say now..can vouch it's a network issue at the location
I am getting constant 5 bars on the 2G network. 3G gives me 2 bars at max.
Asked Vodafone about the future of 3G in my location and they said "We are spreading, sir. We will keep you informed".
I've had this problem too when the phone was constantly switching between 2G and 3G/3.5G. Try adding "Toggle 2G/3G" to notification drawer, set the "Network modes" for it to 2G/3G Only or 2G/3G Only/3G+2G. Switching between modes can take 10-20 seconds, but you should be able to test if you can get good enough 3G only connectivity (in case it is just a network switching problem like for me).
If you want 3G only, Dial *#*#4636#*#* - Phone information - WCDMA only.

[Q] Everytime I reboot I need to rechoose my carrier

I have modded my phone a lot and I think one of my mods may have messed up the search for my carrier after I reboot.
#
The problem:
After I reboot my phone it tells me that I have no carrier selected in the system tray. I click on that notification in the system tray. It takes me to the Network operators screen under settings. Then after about a minute it shows all the operators in the area and I need to select mine.
Possible reason:
When I first got my nexus 4 I thought I could activate LTE. I did activate it but it didnt connect to LTE. After thinking that I didn't activate it properly I tried a series of hacks to try and get lte to work. I tried different radios that supported lte. I tried using *#*#info#*#* from the dialer and changed preferred network type to lte only. Since then I have switched it to GSM auto (prl) since that is the only one my carrier will support.
I think in one of the hacks that I did it screwed up the ability to remember the carrier that I had before the last reboot. I have tried different roms with no luck. Currently I use crDroid. I have updated to the newest version which is currently build16. Is there any thoughts on what I can do to fix this.
I don't reboot my phone often but it's annoying when I reboot to have to fiddle with the phone for over a minute just to get a signal. Even if there was some way to search for carrier quicker I would be happy.
Anyone know how I might be able to fix these issues?

Roaming on VZW after CM13

When I first started using CM13 my signal went to roaming when I know I should have service. I have data roaming off and I've checked to make sure I'm not getting charged for roaming and I'm not. My phone works as it should and I can do everything I need still so I was hoping it would be fixed in one of the new updates. I am on the newest nightly build as of this morning and the R above my signal is still there, just wondering if anyone else is having this problem or know the cause?
I have the same issue on my Nexus 6
Same issue here. Nexus 6 Verizon, just switched to CM13 and I'm stuck on roaming - so far I've tried airplane mode for a minute or two, turning the data off and on, turning the phone off and on, and chatting with Verizon support in case they could do anything remotely. The one thing I haven't done though is try putting another sim card into my phone to see if I could divine any information that way.
Any help would be appreciated.
So after trying just about everything I decided to cave in and jump back to CM12. It was there that I noticed a key difference:
CM12's settings -> mobile network settings, has the following sub-options:
Data Roaming on/off
Preferred Network Type
Enhanced 4G LTE Mode on/off
System select
Access Point Names
CM13 (nightly #2) only has:
Data Roaming
Preferred Network Type
System Select
...while in all honesty I don't know what it all means except to say that it appears to be missing some features of the CM12 nightly I'm using on my Nexus 6 on Verizon. I guess I'll try back in a week or three to see if everything is working fine.
For whatever reason I had LTE pop up for like 2 seconds but went back to R and has stayed since..

UMI Super 3G instead of 4G

Hi,
did anyone using Umi Super have any problems with using 4G at 800MHz? Im on giffgaff and even though Umi Super is supposed to work at 4G under 800MHz (thats what the specification states) i cant manage to make it work. I have perfect 4G coverage, 4G sim, 4G tariff, even gave my sim to a friend with S7 edge and it worked on his phone. Maybe new update will fix that? I tried with different sim from different operator (LYCA) and it works but 4G in LYCA is at 2100MHz so I didnt really check the 800. I tried everything and still nothing. Did anyone have similar problem?
I actually bought 2 phones of the same model so I decided to check if 4G worked on the other one and as I put the sim card in I just remembered something and realized same thing happened with my phone. When I put the SIM card in for the first time it DID automatically go to 4G, ok, when I looked for available networks it found O2 4G, granted BUT!!! when i got to "preferred network type" there is only 3G to pick, and THE MOMENT I PICK IT there is not possible to go back. Every network I find from that moment is only 2G or 3G. Now i reckon that a software problem right? See attachments
It is a software bug and I think I sort it out after flashing the phone. For now I sorted out the problem using Networks app by Philipp Mangalov and switching network to LTE/GSM auto
Well it seems the data part of the UMI SUPER is not so super, is it? I face a similar problem but worse. The 4G band of 800 doesn't work(despite being advertized by UMI as supported) but luckily the band of 2100 works without any issues. The problem comes when I'm out of 2100 band coverage and phone must switch to 3G - then I lose all data connectivity completely. So basically whenever I'm out of 4G 2100 coverage(which is often) I am without any connectivity! Anyone facing the same? Solution?
Indopilot said:
Well it seems the data part of the UMI SUPER is not so super, is it? I face a similar problem but worse. The 4G band of 800 doesn't work(despite being advertized by UMI as supported) but luckily the band of 2100 works without any issues. The problem comes when I'm out of 2100 band coverage and phone must switch to 3G - then I lose all data connectivity completely. So basically whenever I'm out of 4G 2100 coverage(which is often) I am without any connectivity! Anyone facing the same? Solution?
Click to expand...
Click to collapse
I only have 3G and the phone shows that I have internet, but when I try to actually use the data it just says no connection on apps.
zbysogi said:
Hi,
did anyone using Umi Super have any problems with using 4G at 800MHz? Im on giffgaff and even though Umi Super is supposed to work at 4G under 800MHz (thats what the specification states) i cant manage to make it work. I have perfect 4G coverage, 4G sim, 4G tariff, even gave my sim to a friend with S7 edge and it worked on his phone. Maybe new update will fix that? I tried with different sim from different operator (LYCA) and it works but 4G in LYCA is at 2100MHz so I didnt really check the 800. I tried everything and still nothing. Did anyone have similar problem?
Click to expand...
Click to collapse
I don't have this issue at all. My UMi Super connects perfectly to my 4g network under 800MHz without an issue here in Uganda. You can install the MTK Engineering app from the play store and check the band compatibility on ur device and you can also set the mode using the same app under android settings.
You could also try updating to the latest OTA which is 20160810 or the one before it by downloading the files from forum post here and saving them to ur phone and updating manually if you don't have the current OTA
sachak said:
I don't have this issue at all. My UMi Super connects perfectly to my 4g network under 800MHz without an issue here in Uganda. You can install the MTK Engineering app from the play store and check the band compatibility on ur device and you can also set the mode using the same app under android settings.
You could also try updating to the latest OTA which is 20160810 or the one before it by downloading the files from forum post here and saving them to ur phone and updating manually if you don't have the current OTA
Click to expand...
Click to collapse
GravityBox is a perfect solution for this problem. You can set up an icon in notification bar allowing You to toggle between 2G/3G/4G
zbysogi said:
I actually bought 2 phones of the same model so I decided to check if 4G worked on the other one and as I put the sim card in I just remembered something and realized same thing happened with my phone. When I put the SIM card in for the first time it DID automatically go to 4G, ok, when I looked for available networks it found O2 4G, granted BUT!!! when i got to "preferred network type" there is only 3G to pick, and THE MOMENT I PICK IT there is not possible to go back. Every network I find from that moment is only 2G or 3G. Now i reckon that a software problem right? See attachments
Click to expand...
Click to collapse
same problem
This is indeed a software issue, one I have come accross many times - using an app to toggle between the service types is the best workaround!
There are many apps that work to resolve this, some great ones have already been mentioned.
TerryWebbs said:
This is indeed a software issue, one I have come accross many times - using an app to toggle between the service types is the best workaround!
There are many apps that work to resolve this, some great ones have already been mentioned.
Click to expand...
Click to collapse
Could you tell me some app that resolve this?
Thanks
I've got a UMI Super and had this issue as well:
try this app:
Network by Philipp Mangelow
https://play.google.com/store/apps/details?id=de.mangelow.network
4g Umi Super on Giff Gaff
You need Giff Gaff settings in access point name. If you try and use O2 4g it doesn't work even though Giff Gaff uses O2 network. Settings are really easy to input but MUST be Giff Gaff not O2.
zbysogi said:
I actually bought 2 phones of the same model so I decided to check if 4G worked on the other one and as I put the sim card in I just remembered something and realized same thing happened with my phone. When I put the SIM card in for the first time it DID automatically go to 4G, ok, when I looked for available networks it found O2 4G, granted BUT!!! when i got to "preferred network type" there is only 3G to pick, and THE MOMENT I PICK IT there is not possible to go back. Every network I find from that moment is only 2G or 3G. Now i reckon that a software problem right? See attachments
Click to expand...
Click to collapse
There is a fix on rooted phones by using GravityBox and switching between 2G/3G/4G
Thread can be closed.
4G on a Umi Super on GiffGaff.
zbysogi said:
There is a fix on rooted phones by using GravityBox and switching between 2G/3G/4G
Thread can be closed.
Click to expand...
Click to collapse
All that's needed is GiffGaff settings inputing manually. Very easy to do. O2 settings that the phone recognises when a GiffGaff sim is used WILL NOT WORK. The Network is O2 but the APN settings for GiffGaff are totally different.
All you guys that think you know what you're doing obviously don't.
No need to Root or use GravityBox or any other App.
Maz Jones said:
All that's needed is GiffGaff settings inputing manually. Very easy to do. O2 settings that the phone recognises when a GiffGaff sim is used WILL NOT WORK. The Network is O2 but the APN settings for GiffGaff are totally different.
All you guys that think you know what you're doing obviously don't.
No need to Root or use GravityBox or any other App.
Click to expand...
Click to collapse
Well said. I just shake my head in despair when I see how totally clueless people try to be teachers and Internet gurus with very limited knowledge about the task at hand. These comments should come with warning stickers.
For those who want to be able to switch between 3G/4G and LTE only, use this nifty little APK that I've attached below. It will allow you to enter engineer mode without using the dial code.
Hi
This is a bug implemented in Android 7.0.
I had the same.
1 Just force in your parameters 2G/3G networks
2 wait for network authentification (no more excalamtion mark)
3 go back to 4G
Every thing will be OK to next switch off or plane mode.
Rgds,
LTE band 7 (2600) not working
I recently received my new Umi Super and updated to the last firmware V7.01_20170413, everything works fine except for the 4G. I live in an area where band 7 (2600) is available but the phone can't connect to it. Of course, my preferred network type is set to 4G/3G/2G (auto).
I read a lot about the issue on the internet but I can't find a solution.
I checked the BandMode on the phone by dialing *#*#3646633#*#*, band 7 is included and checked. However, when I tried to remove the other LTE bands and keep only band 7, I got a message explaining that the list can't be empty ("Failed. The band is changed from not null to null, it is illegal"), though the list was not completely empty because band 7 was still selected.
Also, I tried to change the radio band by dialing *#*#4636#*#*, but process com.android.phone stopped working when I pressed "select radio band", even after I cleared cache in phone and sim apps.
Can anyone tell me how to fix the problem and get connected to 4G.
BTW, Network by Philipp Mangelow is not available anymore. Switching between 3G/2G and 4G/3G/2G settings doesn't fix the issue. I tried the giffgaff settings, but the APN gets deleted as soon as I try to save it.
Thanks
bemo00 said:
I recently received my new Umi Super and updated to the last firmware V7.01_20170413, everything works fine except for the 4G. I live in an area where band 7 (2600) is available but the phone can't connect to it. Of course, my preferred network type is set to 4G/3G/2G (auto).
I read a lot about the issue on the internet but I can't find a solution.
I checked the BandMode on the phone by dialing *#*#3646633#*#*, band 7 is included and checked. However, when I tried to remove the other LTE bands and keep only band 7, I got a message explaining that the list can't be empty ("Failed. The band is changed from not null to null, it is illegal"), though the list was not completely empty because band 7 was still selected.
Also, I tried to change the radio band by dialing *#*#4636#*#*, but process com.android.phone stopped working when I pressed "select radio band", even after I cleared cache in phone and sim apps.
Can anyone tell me how to fix the problem and get connected to 4G.
BTW, Network by Philipp Mangelow is not available anymore. Switching between 3G/2G and 4G/3G/2G settings doesn't fix the issue. I tried the giffgaff settings, but the APN gets deleted as soon as I try to save it.
Thanks
Click to expand...
Click to collapse
You may try to force 3G and then try to force 4G
You may try to user another IMEI number from a UMI device with 2600 support (of course backup/write down the original one before just in case)
http://www.ucc.co.ug/data/imei/2
After the update to Nougat 7.x how long does it take to do a full recharge?
Do you still have fast charge feature (< 1 hour) or do you lost it like all users reported so far?
What about your GPS? Do you have a fast fix after cleaning history and is it reliable (not losing signal often?).
SimurghXDA said:
You may try to force 3G and then try to force 4G
You may try to user another IMEI number from a UMI device with 2600 support (of course backup/write down the original one before just in case)
http://www.ucc.co.ug/data/imei/2
After the update to Nougat 7.x how long does it take to do a full recharge?
Do you still have fast charge feature (< 1 hour) or do you lost it like all users reported so far?
What about your GPS? Do you have a fast fix after cleaning history and is it reliable (not losing signal often?).
Click to expand...
Click to collapse
Is it safe to change the IMEI number? and where can I find another number for a UMI device?
GPS is working fine, it fixes pretty fast, but I'm not sure about interruption in the signal because I haven't used it enough yet

S8 signal loss in large buildings - other phones have 4G LTE with same sim card

I've been back and forth with Samsung over this. My new S8 (the unlocked USA version, SM-G950U1) has a poor signal in some office buildings, frequently losing signal entirely. Other phones at the same time and place have a strong signal with 4G LTE service. We've tried reflashing the software, changing the sim card, and booting it in safe mode. The same sim card in a different phone gets a signal. I've run Open Signal on multiple phones at the same time to compare results and to show to service reps so they can see what's happening, though that gets me no closer to understanding the source of this problem.
In most places, this S8 works fine and has a great signal. Any thoughts about what could be causing it? Has anyone else experienced this?
Due to summer travel, I didn't catch the problem until after my 14-day return period. Samsung claims I need to mail them the defective one "for repair" and plan to be without my phone for 9-11 days, which seems absolutely crazy to me. (I made a big fuss and they offered to expedite it, but that's still 5 days without my phone.) Looking for last-ditch suggestions... anyone? Thank you!
Edit - more technical details including network screenshots posted here: https://forum.xda-developers.com/galaxy-s8/help/galaxy-s8-unlocked-sm-g950u-maintaining-t3680887
Had the same issue. Had to have to repaired.
They changed everything except the screen and frame.
The issue occured after a software update. After repairs the issue returned after the Orea update... but isnt as bad as before. I seem to have lost Band 5.. 850Mhz
My phone also *just* updated to Oreo, and I think the problem may be back in a milder form. I haven't had a chance to really test or debug it, yet.
My best theory has been that the phone was prioritizing non-LTE signals over a weak LTE signal. How I fixed it the first time: enter the BAND service mode via the native dialer by dialing *#2263# (2263 spells BAND). Clear all bands, then select all LTE bands (ONLY LTE) and apply the changes. This forces the phone to use only LTE signals, no matter their strength. It's worth noting that you may need to alter this when traveling through areas without LTE service, by re-entering the menu and selecting all bands and applying the changes.
Good luck! Please let me know if you figure anything out with your phone after its oreo update!
It is because you will not be on the network band that is stronger
Since flashing my phone back to Nougat I still cannot enable band 20 which I need for better signal. So I’m stuck with poor signal
wezzel98765 said:
It is because you will not be on the network band that is stronger
Since flashing my phone back to Nougat I still cannot enable band 20 which I need for better signal. So I’m stuck with poor signal
Click to expand...
Click to collapse
Are you using the unlocked USA version, SM-G950U1 ? If you load the *#2263# service menu, you can't enable/disable LTE band 20?
If that's the case, I'm not sure why that's happening! When you flashed back to Nougat, did that include a flash back to the baseband you were previously on?
I'm using the g950F from UK unlocked to all networks
Almost all networks rely very heavily on Band 20 in my town to provide good coverage- so with our It I have a major problem
Facing same issue - loss of lte signal - s8+ switching to weaker lte band
Just got the S8+ and updated it to the latest OREO. After detailed diagnosis using service codes, the issue is that the phone is definitely prioritize a weaker LTE BAND Signal during radio activity with the network tower.
Getting full signals on with the same SIM card on other phones.
The new service mode is also not operable or I don't know the key yet. Using *#0011# only shows the SERVICE MODE (Stack 1 & Stack 2), but is not navigable using the Q0 and Q 0000 keys.
Anyone found a solution to this problem or do we have to wait for an update to fix this?
Enter the BAND service mode menu via the native dialer by dialing *#2263#
(2263 spells BAND)
If this doesn't work, what android software build are you running? (It still works for me, on my S8, running oreo G950U1UES5CRL2 )
Solved - jan security patch update
Hi, Just got the update for the JAN SECURITY PATCH UPDATE.
Its working fine now. They fixed the bug. So relieved, finally able to use the handset properly now.
Cheers!
dovesong said:
Enter the BAND service mode menu via the native dialer by dialing *#2263#
(2263 spells BAND)
If this doesn't work, what android software build are you running? (It still works for me, on my S8, running oreo G950U1UES5CRL2 )
Click to expand...
Click to collapse
That's excellent! And also interesting; I'm still waiting for my Jan update, and I'm hoping the delay means it will be my PIE upgrade... *crosses fingers*

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