Tutorial: How to Downgrade to Android Marshmallow

Hi ZenFone 3 users, I'll show you guys how to downgrade your phone to Android Marshmallow.


Step 1: Download the RAW firmware

ZE520KL : Link
ZE552KL : Link

Step 2: Download ASUS Flashtool
Link

Step 3: Download 13.20.10.152 firmware from ASUS' website and put it in the root of your SD card.
ZE520KL: Link
ZE552KL: Link

Step 4: Enter Fastboot Mode on your device by pressing Power Button and Volume Up Button simultaneously.

Step 5: Connect your phone to the PC and open ASUS Flashtool

Step 6 : Select your device model.

Step 7: Flash the RAW firmware.

Step 8: After flashing the RAW firmware, power off your device and enter recovery mode (Power Button + Volume Down Button)

Step 9: Install 13.20.10.152 firmware (Apply update from microSD card)-(Use Power Button to select and use Volume Buttons to navigate)

Step 10: Factory Reset your device

P.S: Before downgrading, please backup all of your important data to prevent data loss and I AM NOT RESPONSIBLE FOR BRICKING YOUR DEVICE.

Video Tutorial : https://youtu.be/P8xg7A-P7Ak

Have successfully done this, the camera of my phone is still blurry... you think it may be a hardware problem already?

kelvincharlescaro1988 posted on 2017/8/14 16:31
Have successfully done this, the camera of my phone is still blurry... you think it may be a hardwar ...

Try to flash light on the camera lens and see if it works.

negative. lol. I'm about to give up hahahah

Hi, do I really need a SD card? Can I just use the internal storage instead?

AleksanderV posted on 2017/9/10 14:34
Hi, do I really need a SD card? Can I just use the internal storage instead?

Yes. SD card is really important for this process.

saktis_impreza posted on 2017/9/10 16:56
Yes. SD card is really important for this process.

Thanks for your quick response, guess I'll have to buy a SD card just to downgrade my phone then. The Nougat battery drain is so freaking horrible. Btw, is 13.20.10.152 the most stable one?

AleksanderV posted on 2017/9/10 17:26
Thanks for your quick response, guess I'll have to buy a SD card just to downgrade my phone then.  ...

Not really though, but it is still better than Nougat.

saktis_impreza posted on 2017/9/10 17:30
Not really though, but it is still better than Nougat.

After having tried some custom ROMs (only about 3 and not so stable tho, this phone seems not so popular), I decided to switch back to 6.0 stock room (thank you for the nice guide), since as long as it's N, there will still remain a huge battery drain. Now I can finally use this phone without having to plus the charger at least twice a day, lol. Kudos to you mate

I've read somewhere that there will be a O update for zenfone 3 sometime in 2018, hope it will be optimised well. I might just stick with this Marshmallow build if the battery issue would still be there...