Hi
Rifqi1209Thank you for your asking. Kindly provide the information below so that we can better assist you.
A. Does the issue appear right after the system update?
B. Please try the following steps to access recovery mode for the Factory Reset:
0. Try to back up your data with USB cable. If you can not access the phone, please check if your google account or microSD card have auto backup your data.
1. Power off the phone, then keep pressing "volume down key"
2. Press "power key" and stop press " power key" once you feel the vibration. Still keep pressing "volume down key".
3. Stop press "volume down key" once you enter [Android Recovery] Screen
4. Choose "Wipe data/factory reset">"Yes"
5. "Reboot system now"
#Hardware Reset Guide
[ZenFone] How to do hardware reset on your phone? | Official Support | ASUS Global**Please note that once the steps are completed, all data, apps, settings and personal information will be deleted.
[Phone] How to back up the data stored in your phone ? | Official Support | ASUS GlobalC. Please put the WW-15.2016.1809.412 file into microSD card and try to re-flash the system again.
ZenFone4 Max (ZC554KL) - SupportInsert MicroSD card into phone and then power off the device> follow aforementioned steps to enter [Android Recovery] Screen> Choose "Apply update from external storage"> Select the downgrade file> When the updating process is done, Choose "Wipe data/factory reset" and tap "Yes" to perform the master clear> "Wipe cache partition" > "Yes"> "Reboot system now"
If the issue still remain, please contact ASUS repair center in the country of your residence:
https://www.asus.com/support/Service-Center-All-Countries/If it is impossible to access the service center during Covid-19 period, please try CallUs:
https://www.asus.com/support/CallUs**Please backup before you submitted to the repair center.