Update Huawei Ascend P7 L10 to Android 5.1.1 !

UDPATE: Because of certain issues with the initial article, I’ve researched the update process thoroughly and updated the article accordingly, to resolve the initial direct B830 update issues.

I was a bit tired of waiting for the stupid Android 5.1.1 (Lollipop) update to show up within the phone updater, so I’ve taken things into my own hands…

Here is what you need:

  • Huawei Ascend P7 (unbranded European P7-L10 only!) smartphone with fully charged battery
  • microSD card inserted in the phone
  • USB cable
  • 7-zip, WinRAR, PeaZip or other archiver capable of unpacking archives with updates

Plus the following updates:

Latest update:

You have to first have B839 installed on your phone before you can upgrade to B852. OTA updates are incrimental and they have to be installed in a correct order! B839 -> B852 !

This update ONLY supports following existing builds:


Check Settings -> About Phone -> Build number if numbers match. In my case, the first one was a match, the XXX can be any number, it was 135 in my case followed by SP04. But I don’t think that’s important. BXXX numbers however are very important!

If they don’t match, anything you do in advance is on your own risk! I recommend you don’t update it if the version numbers don’t match.

Updating process for versions lower than B621

I recommend wiping the phone prior updating to avoid potential issues. Backup your internal data and transfer/deactivate your Google Authenticator codes before you perform factory reset!

  1. Download B621 firmware, unpack archive and copy entire dload folder to your Ascend P7 microSD card root using USB cable.
  2. Turn off your phone. Wait for it to fully shut down.
  3. Press VolumeUp+Power buttons and release them when logo appears on screen.
  4. Select Wipe Cache partition and then Wipe data/factory reset.
  5. Restart the phone and skip all the first start settings.
  6. Shut down the phone.
  7. Press VolumeUp+VolumeDown+Power buttons until the phone starts. This will force install B621 update.
  8. Download B621 CUST Hotfix, unpack it and copy entire dload folder to microSD card. This will replace old update files (confirm overwriting the files).
  9. Shut down the phone.
  10. Press VolumeUp+VolumeDown+Power buttons until the phone starts. This will force install B621 CUST Hotfix update.
  11. Download B830, unpack it and copy entire dload folder to microSD card. This will replace old update files (confirm overwriting the files).
  12. Shut down the phone.
  13. Press VolumeUp+VolumeDown+Power buttons until the phone starts. This will force install B830 update.
  14. Download B839, unpack it and copy entire dload folder to microSD card. This will replace old update files (confirm overwriting the files).
  15. Shut down the phone.
  16. Press VolumeUp+VolumeDown+Power buttons until the phone starts. This will force install B839 update.
  17. DONE!
  18. Setup your phone by adding Google Account or simply factory reset it again for first start setup wizard to appear.

It looks complicated, but after step 7, it’s basically a repeating task for each build.

Updating process if you are running a version B609 or newer

If you’re using B609 or later (because your phone arrived with it when new or it updated itself to this version), you should be fine updating directly to B839, but you strictly have to use a full version update which is around 1,5 GB in size (the above link).

Updating process if you have already updated directly to B830 or B839 and you’re experiencing functionality problems

If you have upgraded from lets say B135 directly to B830 or B839, like I have, you have most likely experienced several issues after doing factory reset. Missing keyboard, lockscreen and wallpaper images locked together, missing Motion Control settings etc. In this case you have to first downgarde your phone back to B621. You have to use the same chain of upgrades, just in reverse to downgrade your phone. I had B839 installed, so I had to first downgrade it to B830 and then B621. Made a factory reset and then repeated the above B621 updating process, step by step. Updater may say that firmware upgrade failed in the very end of each downgrade, but don’t worry, it will work anyway. You can check your build version number on each downgrade step if you want to be sure. Going back from B621 to B839 should not show any more FAILED messages. It should successfully update them.

Why all these problems appear?

Apparently the CUST issues happen when manually transitioning from Huawei’s EMUI 2.x custom interface to latest versions that use EMUI 3.x. It somehow conflicts. But if it’s already running EMUI 3.x, there should be no problems updating directly to latest version.


Everything is working perfectly now, no issues, no missing features, just the latest OS and super smooth functionality. From now on, you should receive updates through integrated updater or by new builds (I might update the article with that in the future). Android 6.0 (Marshmallow) is allegedly also planned even for Ascend P7, so it might be interesting. We’ll see…


PS: If you need any extra info, ask me down below and I’ll check it out for you.

106 thoughts on “Update Huawei Ascend P7 L10 to Android 5.1.1 !

  1. Here’s my problem…I have the Ascend P7-L10 B839 firmware and when i try to install the b852,it says that software install has failed..What should i do?
    Thanks in advance!


    1. I had a similar problem. If you have the files as “update.zip” try leaving the files unextracted and just copy the zip file into the dload folder, didn’t run into any issues after doing this


  2. Hello I live in South Africa, my Huawei build number P7-L10V100R001C00B135SP03. Can I flash my opperating system with your wonderfull method? Thanm you do much for your time in prepairing these updates for us. I have my phone almost 2 years now and still no official OTA updates from Huawei. Thanks. Mike


  3. I updated from C00B173 and got as far as B830 then phone told me to update to B852.I tried B839 just in case but update failed so used b852 and all is fine


  4. I am trying your method and I am on step #7, but it is taking forever. It has been like an hour and the phone still says software installing. Does it take that long? What can I do?


  5. I have the P7_L10 build number B136 I did as you say but when I tried to unpack the B839 update it said the file is corrupted I tried to unpack the B852 same thing happened what should I do now.


    1. Your downloads are getting corrupted because your connection has problems or it’s your system that has problems. Downloads are fine integrity wise.


  6. my Huawei Build number is P7-L10V100R001C02B123. So I was wondering if this one of mine can be updated to v5.1.1 (Lollipop) since my Huawei is inffected by virus called lutu, even when I reset my phone the virus doesn’t get off. So I want to know if updating it to this lollipop version will it also help by getting the virus off in my phone. Please Help Me.


    1. updating/flashing phone will remove virus if it is a virus and not some website that is telling you that you have virus. Anyway I would advise you to update as shown above and on the extremely rare chance you still have”virus” I would flash update by fastboot but that is slightly more complicated to do.Good Luck


  7. HI, I live in South Africa and have build no P7-L10V100R001C00B133SP01. How can I safely upgrade to 5.1.1? Do I also have to install all the updates stated above, from B621 to B839? How big are these files? I have a 32gig micro SD card, is that big enough? If I download these upgrades, will it wipe all the data from my phone, i.e. reset everything, or will I still have all my contacts, photos, personal settings, etc?
    I’m not very tech savvy when it comes to IT talk, so please be very clear. Thank you


  8. The upgrades will not wipe your data.As for update size some are nearly 2GB.What you do is install first update then copy 2nd “update app” and paste to dload folder.You will be asked by Windows if you want to “copy and replace”,you click on that option which will delete update 1 and replace it with update 2.You then install that and work your way through the updates doing the same again.NB It looks like you have to go through the whole process from your build number,like myself,.I got to B830 and huawei prompt me to update straight from phone to latest firmware so check SETTINGS-UPDATES before downloading B839


    1. Hi Kevin. Thanks for that. One last stupid question: do i connect my phone to my computer and download all the updates to my computer and from there to my phone?


      1. Download updates to computer and copy one by one to DLOAD folder on sd card(you might have to create folder yourself before starting) I am not sure if CUST fix comes as “update app” like the rest but anyway you can delete when successfully installed


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