Mi8 EE no LTE signal. only 3G or EDGE


bentstan

Members
Nov 3, 2019
8
3
Hey guys,
since 2 weeks my Mi8 EE cant connect to LTE anymore. Dont know if it is since an update or what happened that it cant connect.
I had the weekly rom from here installed, waited 1 or 2 updates but nothing changed. Then I decided to check the SIM in my old phone and there I had immediately LTE signal. So it can only be the phone. (also testet another SIM and with another phone. Same situation).
I flashed the latest Chinese ROM with MiFlash Tool in fastboot Mode, but there was also no lte connection available.
Somehow my sensors were broke then, so I reflashed the persist.img and everything is fine with them now. But LTE is still not working.
Any ideas? Thanks.
 

Karpfenhai

Members
Jul 17, 2016
490
67
Hey guys,
since 2 weeks my Mi8 EE cant connect to LTE anymore. Dont know if it is since an update or what happened that it cant connect.
I had the weekly rom from here installed, waited 1 or 2 updates but nothing changed. Then I decided to check the SIM in my old phone and there I had immediately LTE signal. So it can only be the phone. (also testet another SIM and with another phone. Same situation).
I flashed the latest Chinese ROM with MiFlash Tool in fastboot Mode, but there was also no lte connection available.
Somehow my sensors were broke then, so I reflashed the persist.img and everything is fine with them now. But LTE is still not working.
Any ideas? Thanks.
Check your preferred network, no issue on mine:





Regards

Sent from my MI 8 Explorer Edition using Tapatalk
 

bentstan

Members
Nov 3, 2019
8
3
Preferred Network Type is set on GSM/WCDMA/LTE. I checked also the additional Options, especially the modem tools, in the CIT Menu. There it was set to LTE/UMTS (PRL).
Anyway, if I set one of them to LTE only i just get no signal. Meanwhile I think this is a hardware defect... or maybe you have another idea?

I also reset the APN: nothing changed. And setting up the APN manually for vodafone didn't help either.

28160
 
Last edited:

Karpfenhai

Members
Jul 17, 2016
490
67
Preferred Network Type is set on GSM/WCDMA/LTE. I checked also the additional Options, especially the modem tools, in the CIT Menu. There it was set to LTE/UMTS (PRL).
Anyway, if I set one of them to LTE only i just get no signal. Meanwhile I think this is a hardware defect... or maybe you have another idea?

I also reset the APN: nothing changed. And setting up the APN manually for vodafone didn't help either.

View attachment 28160
Hmm, that's weird then, I guess you already tried the other Sim slot? What happens with another carrier Sim card in your device?

Also try one of the helper tools, maybe they shed some light?



Sent from my MI 8 Explorer Edition using Tapatalk
 

bentstan

Members
Nov 3, 2019
8
3
yes, I tried the other SIM slot already. Another carrier Sim card is a good idea. Will try this later when my friends come over.
Which helper tools do you mean?
 

Karpfenhai

Members
Jul 17, 2016
490
67
yes, I tried the other SIM slot already. Another carrier Sim card is a good idea. Will try this later when my friends come over.
Which helper tools do you mean?
Lte discovery and such

Sent from my MI 8 Explorer Edition using Tapatalk
 

bentstan

Members
Nov 3, 2019
8
3
I dont know really what I can read there (LTE discovery) but I get only information about my EDGE Connection. Every LTE related section is marked with N/A.
On the other hand do you know if all modem related partitions are overwritten when I flash a fastboot rom with MiFlash?
Because in this case I would argue that it should work?
 

Karpfenhai

Members
Jul 17, 2016
490
67
I dont know really what I can read there (LTE discovery) but I get only information about my EDGE Connection. Every LTE related section is marked with N/A.
On the other hand do you know if all modem related partitions are overwritten when I flash a fastboot rom with MiFlash?
Because in this case I would argue that it should work?
Afaik the Modem is a part of the Rom yes, so the test button doesn't do a thing then? Hmm it seems your device “thinks“ it doesn't have lte Bands.. Since you already clean flashed everything..we're out of options, try to go back to an earlier Rom, way earlier, like oreo.

Or try to flash the modem only.

Did you test a different Sim?

Sent from my MI 8 Explorer Edition using Tapatalk
 

bentstan

Members
Nov 3, 2019
8
3
Okay, will try to go back to an early version and let you know. I only tried Pie and this didn't help.
And yes, some minutes ago I tried an O2 SIM card but there was also only E available... :(

If that all doesnt help, I'm going send it to my insurance..
 

zapatto

Members
Jan 24, 2020
3
3
Okay, will try to go back to an early version and let you know. I only tried Pie and this didn't help.
And yes, some minutes ago I tried an O2 SIM card but there was also only E available... :(

If that all doesnt help, I'm going send it to my insurance..
Hey! Did you find out how to fix it?
Im having the same problem in Argentina with my Note 8.
Someone said it may be the ROM... i have the 11.0.4. Global.. I believe is the latest.. Another guy said that Xiaomi phones have a software that "blocks" the bands of some countries and i have to change the ROM... i think this is nonsense...
I cant find out how to make it work.. is not the sim card because i can recive calls and sms.. so the sim its working but im not getting internet, non 3g non 4g.. internet works only with WIFI
 

bentstan

Members
Nov 3, 2019
8
3
Hey! Did you find out how to fix it?
Im having the same problem in Argentina with my Note 8.
Someone said it may be the ROM... i have the 11.0.4. Global.. I believe is the latest.. Another guy said that Xiaomi phones have a software that "blocks" the bands of some countries and i have to change the ROM... i think this is nonsense...
I cant find out how to make it work.. is not the sim card because i can recive calls and sms.. so the sim its working but im not getting internet, non 3g non 4g.. internet works only with WIFI
Nope, I haven't figured it out yet. Rolling back to the initial release ROM for my device didn't help either.
Next week I'll try again to fix it...
But your problem sounds very similar. Meanwhile I get only connection over EDGE also...
 

zapatto

Members
Jan 24, 2020
3
3
Nope, I haven't figured it out yet. Rolling back to the initial release ROM for my device didn't help either.
Next week I'll try again to fix it...
But your problem sounds very similar. Meanwhile I get only connection over EDGE also...
Ive spoken with my mobile company they tried to help me with the connection, but it doesnt work anyway. They gave me the Xiaomi contact but they response is like every 3 days (they take some time on answering). So today I told them my situation, now im waiting the response, maybe next week i will have an answer..
Which ROM do you have? Mine is 11.0.4
Rolling back phone software is not a good idea... I had bad experience doing that on a Samsung Galaxy S2 (some years ago) and in a DJI Drone... i got a beautiful paperweight
 

Karpfenhai

Members
Jul 17, 2016
490
67
Ive spoken with my mobile company they tried to help me with the connection, but it doesnt work anyway. They gave me the Xiaomi contact but they response is like every 3 days (they take some time on answering). So today I told them my situation, now im waiting the response, maybe next week i will have an answer..
Which ROM do you have? Mine is 11.0.4
Rolling back phone software is not a good idea... I had bad experience doing that on a Samsung Galaxy S2 (some years ago) and in a DJI Drone... i got a beautiful paperweight
But no Internet at all seems to be a apn issue, try to create one manually.


Sent from my MI 8 Explorer Edition using Tapatalk
 

bentstan

Members
Nov 3, 2019
8
3
Ive spoken with my mobile company they tried to help me with the connection, but it doesnt work anyway. They gave me the Xiaomi contact but they response is like every 3 days (they take some time on answering). So today I told them my situation, now im waiting the response, maybe next week i will have an answer..
Which ROM do you have? Mine is 11.0.4
Rolling back phone software is not a good idea... I had bad experience doing that on a Samsung Galaxy S2 (some years ago) and in a DJI Drone... i got a beautiful paperweight
I was on weekly 20.1.16, but I first noticed the bug on 20.1.9 (I think so).
Did you get an answer from Xiaomi already?

The only thing I could archive the last days was to get 3G/H signal back. Somehow only Edge was available after like hundreds of flashes.
Got it back with restoring an old backup from octobre last year. So seems like a software issue for me. I found many threads to this issue and many different ways of solving. Tried some of them, nothing changed. Most of them lost their IMEI and they tried to recreate the EFS Partition. Of course I have no EFS Backup (hate myself for that) to try that, but since both IMEI are available for me this shouldn't be the issue... or what do you think?