[Xiaomi Redmi 2] Is possible to unlock Basebands?

[korolirio]

Hello. I have a Xiaomi Redmi 2 2014811 subversion which doesn't have the 850 GSM band that I need in the rural area where I live.
I have seen that the submodel 2014819 (Brazil) has this band and I would like to know if is possible to change the baseband by flashing any software.
In other words: Are submodels 2014811, 2014819 the same hardware with different radio/modem partition softwares or have they different hardwares?
I have seen that with other mobiles like Moto E 2015 is possible to change the region of the baseband by software:
http://forum.xda-developers.com/moto-e-2015/help/question-models-bands-t3163453

Thanks

 

[russelgrim123]

I hope someone can help you with this

 

[Lennoard]

Hi, I'm Brazilian and got the HM2014819, as soon as I get the partition table I will upload it for you TO TRY of course after a Nandroid Backup by you. I will upload if the size match with my data plan :good:
Well, I don't know if you will can successfully flash it, and if it will work.
Going to dump the modem here in a .img that you can flash or make a flash zip

 

[korolirio]

Thanks Lennoard, but I think is not a modem issue. I am on the way to Unlock the GSM bands in the Qualcomm, if it would be possible.
I have followed all the steps in
- Unlocking Basebands on MI4 (http://forum.xda-developers.com/mi-4/general/unlocking-basebands-mi4-t2879685)
- Unlock all bands of your Qualcomm device! Use your phone globally! No bs! (http://forum.xda-developers.com/cro...ad-progress-please-leave-im-updating-t2871269)
- [Q & A] how can i enable qualcom diagnostic mode? SOLVED (http://en.miui.com/thread-100458-1-1.html)
Now, if I read the NV_RF_BC_CONFIG_I (#1877) from phone, the value is changed and all GSM and WCDMA bands are enabled, included the GSM 850 MHz band.
But I cannot connect to any GSM band and doesn't recognize any GSM provider in the area.
Bad luck
Anybody has tried this way with success?
Thanks

 

[korolirio]

Anybody changed the basebands of a xiaomi redmi 2 in the qualcomm way with success?

 

[b1h]

I've tried the Qualcomm method and so far it's not working. Whenever I tried to add GSM/WCDMA bands, my phone keeps restarting. But, I can confirm that I can disable bands. When I tried to add LTE bands 5(850mhz) and 28(700mhz), the phone didn't restart but after disabling all other LTE bands, I'm quite sure the phone couldn't detect those bands. I don't think I can enable it because well... someone with an OPO couldn't... and 700mhz is just really low...

I don't know what's causing my phone to restart everytime I've added additional bands. What rom and you using? I'm using resurrection remix.

 

[korolirio]

I don't know what's causing my phone to restart everytime I've added additional bands. What rom and you using? I'm using resurrection remix.

Thanks. Now I doesn't feel so lonely.
I did the changes of NV with MIUI v7 installed in the phone and indeed, the changes are still present and the mobile works exactly like before the changes. I read the NV and the bands are enabled, but still doesn't connect to any different bands than before.
It is strange the behaviour you get with a different rom. The NVs should be not affected by the ROM, it isn't?
Which submodel of redmi 2 do you have? Is possible that different hardware or antennas could be assembled in the different submodels of this mobile?
Thanks

 

[b1h]

Thanks. Now I doesn't feel so lonely.
I did the changes of NV with MIUI v7 installed in the phone and indeed, the changes are still present and the mobile works exactly like before the changes. I read the NV and the bands are enabled, but still doesn't connect to any different bands than before.
It is strange the behaviour you get with a different rom. The NVs should be not affected by the ROM, it isn't?
Which submodel of redmi 2 do you have? Is possible that different hardware or antennas could be assembled in the different submodels of this mobile?
Thanks

I'm using 2014813, I wanted to add 900mhz wcdma which 2014811 has, but I chose 2014813 because it supported more lte frequencies that my carrier uses. There's also some lte frequencies that both models don't support which I tried to add.

I'll try to add bands with miui tomorrow.

 

[korolirio]

I'll try to add bands with miui tomorrow.

Ok. I am waiting for your results.
Good luck

 

[b1h]

Ok. I am waiting for your results.
Good luck

I've flashed miui. So far instead of my phone restarting after trying to connect, the radio keeps turning off and on.

 

[korolirio]

Ups! What a different behaviour! Is it maybe because you are changing the NVs for 4G/LTE? I only enabled all the 2G and WCDMA (3G) Bands and didn't changed anything in the 4G and my phone just works and detects networks exactly like before, nothing looked like to change.

 

[b1h]

Ups! What a different behaviour! Is it maybe because you are changing the NVs for 4G/LTE? I only enabled all the 2G and WCDMA (3G) Bands and didn't changed anything in the 4G and my phone just works and detects networks exactly like before, nothing looked like to change.

Have only messed with 2G/3G so far, adding 900mhz wcdma is still causing issues for me. I can enable 850mhz gsm but I don't know if it would actually work because no carrier uses 850mhz gsm here.

What are the steps you did to try to get 850mhz gsm to work?

 

[korolirio]

Have only messed with 2G/3G so far, adding 900mhz wcdma is still causing issues for me. I can enable 850mhz gsm but I don't know if it would actually work because no carrier uses 850mhz gsm here.

According to the specs:
HM2014813 Is "China Mobile 4G Dual-Sim Version". It Supports These Network Bands/Frequencies:
4G Network : TDD-LTE (B38 / B39 / B40 / B41: 2555-2655 MHz); FDD-LTE (B3 / B7)
3G Network : TD-SCDMA (1900 / 2100 MHz); WCDMA (850 /1900 / 2100 MHz)
2G network : GSM (900 / 1800 / 1900 MHz)

The phone should have an antenna capable to work at 900 MHz, because it uses this frequency for GSM, then, adding support for WCDMA 900 MHz is not a radio issue but a logic one. Doesn't it?

What are the steps you did to try to get 850mhz gsm to work?

I basicaly followed this steps:
Unlock all bands of your Qualcomm device! Use your phone globally! No bs!
http://forum.xda-developers.com/cro...ad-progress-please-leave-im-updating-t2871269
I enabled all the bands using the NV calculator and saved the value that after restarting is still stored, but nothing changed. The phone is working since this (2 weeks ago) exactly like before, no any strange behaviour.

Then... still there are no signs of anybody saying that this method works with this model.
But I don't loose the faith

 

[b1h]

According to the specs:
HM2014813 Is "China Mobile 4G Dual-Sim Version". It Supports These Network Bands/Frequencies:
4G Network : TDD-LTE (B38 / B39 / B40 / B41: 2555-2655 MHz); FDD-LTE (B3 / B7)
3G Network : TD-SCDMA (1900 / 2100 MHz); WCDMA (850 /1900 / 2100 MHz)
2G network : GSM (900 / 1800 / 1900 MHz)

The phone should have an antenna capable to work at 900 MHz, because it uses this frequency for GSM, then, adding support for WCDMA 900 MHz is not a radio issue but a logic one. Doesn't it?



I basicaly followed this steps:
Unlock all bands of your Qualcomm device! Use your phone globally! No bs!
http://forum.xda-developers.com/cro...ad-progress-please-leave-im-updating-t2871269
I enabled all the bands using the NV calculator and saved the value that after restarting is still stored, but nothing changed. The phone is working since this (2 weeks ago) exactly like before, no any strange behaviour.

Then... still there are no signs of anybody saying that this method works with this model.
But I don't loose the faith

I don't know if antenna placement is different but the modem between the sub models aren't compatible with each other. This is what I would need to do to get any signal at all.

With mztool, try selecting only 850mhz gsm and edit the RF BC Config as well as the Band Preference values and see what happens.

 

[b1h]

I think I might need to conclude that I have not been able to get 900 mhz wcdma working on my 2014813 despite the 2014811 having it. Also with LTE I haven't been able to unlock any additional bands.

 

[motahu]

Hii all, I'm interested with this topic too.
I would like to add LTE band40 which 2014813 has.
What happen if i flash baseband from rom 2014813 to 2014811 ?
Here my baseband radio on crdroid [imgur.com/wgrMqPk]

 

[b1h]

Hii all, I'm interested with this topic too.
I would like to add LTE band40 which 2014813 has.
What happen if i flash baseband from rom 2014813 to 2014811 ?
Here my baseband radio on crdroid [imgur.com/wgrMqPk]

Flashing the 2014813 modem on your 2014811 would probably lose your signal. This or this is what would need to be done if you have a 2014813 and flashed a rom with a 2014811 modem in it.

 

[motahu]

Happy new year to you, all. @MagMar I already try to flash 2014813 modem to my 2014811..it is no signal but imei n baseband are find..but my 4g card display correctly at lte discovery..so maybe you can share nv config value (like nv 1877, 6828 n 2others) that 2014813 have...n i think lte freq dependent with 3g freq also

 

[b1h]

Happy new year to you, all. @MagMar I already try to flash 2014813 modem to my 2014811..it is no signal but imei n baseband are find..but my 4g card display correctly at lte discovery..so maybe you can share nv config value (like nv 1877, 6828 n 2others) that 2014813 have...n i think lte freq dependent with 3g freq also

While I've flashed 2014811, my phone does recognise the imei and baseband but it'll tell me that I have no service. Both models do share some of the same bands so it should be able to connect assuming both models have a supported band to the carrier. This is why I think that flashing different modems and editing the NVs won't work.

 

[kgbking]

I'm using 2014813, I wanted to add 900mhz wcdma which 2014811 has, but I chose 2014813 because it supported more lte frequencies that my carrier uses. There's also some lte frequencies that both models don't support which I tried to add.

I'll try to add bands with miui tomorrow.

Mine is 2014813(running a mokee 60.1 rom), too. I've tried to add wcdma 900 through changing the four nv values specified by the mztool and fdd b1&b8 through changing the lte_bc_config nv value. So far everything seems to be fine. While, I not sure whether those changes are successful or not. Do you have any idea how to confirm that those added bands are working or not?