ASUS ZENFONE 2 LASER 5.5s (ZE550KL) MARSHMALLOW 6.0.1 UPGRADE

This tutorial is for Asus Zenfone 2 Laser 5.5s (ZE550KL)-Z00LD marshmallow upgrade from my current Lollipop version which was rooted via Kingroot app.

Since I'm already rooted I would no longer be able to access auto update via system update but would simply do the upgrade manually.

If your phone is not rooted then simply download the chosen firmware of your liking and just save it to your internal storage by transferring through PC after download.

Disclaimer: I'm not held responsible if anything happens to your device, do it at your own risk!

I have downloaded the latest Marshmallow firmware from Asus website itself (here) which is Version WW-21.40.1220.2196, just make sure you are downloading the same SKU (WW for WW, TW for TW, CN for CN) that you can check out from your system information from settings.

Asus_Zenfone_2_Laser_(ZE550KL)_Android_M_firmware

You can select other models if you are not using the same model as per this tutorial by tapping "select other model" to find your device.

Asus_firmware_download

Then just try to input your own model by filling up the form as shown.

Asus_firmware_download_select_other_model

note: for rooted Asus Zenfone 2 Laser 5.5s (on Lollipop version) will definitely be un-rooted after the upgrade or will have no root access but still having a bootloader that is unlocked upon checking. 

Things Needed:
1. Android M firmware zip file (latest)=Version WW-21.40.1220.2196
2. Android L firmware zip file (latest)=Version WW_1.17.40.1531 *for those who have lower L versions installed before upgrading to M*
3. Stock boot.img and Stock recovery.img -for rooted phones before upgrading to M (these are stock img from the latest Android L with version WW_1.17.40.1531)
4. ADB installed in PC

***click on boot.img and recovery.img above to download file***

STEPS:

Non-rooted Asus Zenfone 2 Laser 5.5s 

1. For non rooted Asus Zenfone 2 Laser 5.5s make sure you are within the latest Lollipop version of Version WW_1.17.40.1531 (2016/05/13) before you upgrade to any Marshmallow update, same goes with the other models you must first upgrade to the latest Lollipop version for your models (try to google if different device).

Asus_Zenfone_2_Laser_(ZE550KL)_Android_L_firmware

You can check by going to settings>about>software information and check on your Build number and you can check the date of your own kernel version as well which almost match your build number after your firmware version.

software_information

2. Downloading the latest Marshmallow update zip version as shown below via PC or if you could use your phone directly and save or move to your internal storage.

Version WW-21.40.1220.2196_Android_M_update

3. After downloading your Marshmallow update zip file make sure to use your zip program or whatever you use to extract files on zip extensions and test if your downloaded zip file is not corrupt before transferring to your internal storage

test_downloaded_zip_file_if_not_corrupt

tsted_files_ok_0_failed

4. Reboot phone after the transfer but if your phone could already detect the update file which will show up from your notification status bar of a triangle icon with an exclamation point upper left top corner of your phone then simply tap and select the update.

system_update_notification

select_system_update

select_Android_M_firmware

5. Wait as you should be able to see the little cute green android from your screen installing the update and restart/reboot system once it has completed the installation process.

system_update

Congrats you just upgraded from Lollipop to Marshmallow version. Enjoy!

note:
If you happen to be on a lower version of Lollipop simply download the latest "L" version and do the same steps above saving from internal storage and installing the update before you proceed with "M".

If downloading the latest "L" would not work then follow steps below from quick fix by flashing the stock boot.img and stock recovery.img of 1531 via adb on fastboot mode then click on system update notification after reboot.

************************************************

STEPS:

Rooted Asus Zenfone 2 Laser 5.5s 

Since mine was rooted I was not able to update even if I saved the Marshmallow firmware into my internal storage and giving me errors like this one "Can't install this M Package...L less than 20160426 build" when doing the steps above.

My version have the same name as the latest Lollipop except of a different date 20160428 against what was posted from download site section of 2016/05/13 while the error telling me I am less than 20160426 when I'm not as I'm ahead of two days but may be due to the boot.img and recovery.img as what I read from other tech experts.

software_information

I rebooted to recovery via TWRP and tried to install the Version WW_1.17.40.1531 (2016/05/13) to see if it will work out because of the date difference to my actual version but getting again another error as shown.

TWRP_install_zip_Version WW_1.17.40.1531 (2016/05/13) 

Now it's telling me to use the right SKU when I am using the right one. So I looked for the stock boot.img and recovery.img that I need to flash via ADB.

First thing first just save the "Android M" firmware from your internal storage, just disregard the "Android L" firmware since it failed when I tested as shown above.

Version WW-21.40.1220.2196_Android_M_update

QUICK FIX WHEN UPGRADING ROOTED ASUS ZENFONE 2 LASER 5.5s (ZE550KL)

1. Connect your phone to your PC and open a new command from your adb platform tools and make sure you copy and paste the stock boot.img and recovery.img inside the platform tools folder  as shown below. Don't forget to enable "USB debugging" under developer options from your device.

open_command_window_from_adb_platform_tools

2.  Now once you have your command window simply type the following as follows

adb devices (hit enter)

adb reboot bootloader  (hit enter)

fastboot flash recovery recovery.img  (hit enter)

fastboot flash boot boot.img  (hit enter)

fastboot reboot  (hit enter)

adb_command_window_boot_bootloader

3. Just reboot your phone and once your phone rebooted just like from the normal non rooted device steps, click on the system update notification that will appear from your status bar and click and update.

4. Wait as your phone will install the system update and reboot to your new Marshmallow version.

Congrats and enjoy your new Android M version, though the 20180308 from system information did not match as per post from their download sites which was supposed to be 2018/04/18 or unless just the release date but doesn't matter as long as it's already Android verison 6.0.1

New_Android_M_6.0.1

Just expect for added bloatware apps as usual as it's already a trademark for Zenfone developers pushing apps that you don't really need. You may use root explorer app to check from system/app and system/priv-app, check removal bloatware from this thread (here).

If you happen not to see the Asus Music app that was replaced by Google music app after the marshmallow update, just go to your system/priv-app where it was saved but not installed and you can install if you like.

Here's a screenshot showing that the bootloader is unlocked after the upgrade to Marshmallow.

bootloader_still_unlocked

Tried to install Kingroot to root again my device but failed, tested the new version app but could not be installed either unless you opt for install(unsafe) but could not do the job to root the device this time.

no_root_access

Still working on how to revert back to stock Version WW_1.17.40.1531 if possible using the same steps above. You may now visit this post using adb sideload to get back at stock 1531 version (L).

credits to stock boot.img and recovery.img to shakalaca.

Until next post...How to fix bootloop, auto restart, brick Asus Zenfone 2 Laser 5.5s (here)

Share with friends if you found this tutorial helpful.

Enjoy!