I'll give you a link to download the file and steps. But I would like to quote a few things to read and I would in no way be responsible for any damages that may be caused by this manipulation, you are aware of the risks:
1 - Remember to send the unit to Acer if your warranty is still valid may be better.
2 - This method worked with me it does not necessarily mean it will work with you.
3 - The version of my device "Acer Z2 WW 1.007.00 GEN1
" and I think this update is specifically for this version, remember to check your version (maybe there were different versions for device)
4 - My device "Acer Z2 Duo
" (dual sim)
The steps to follow.
1-Download the file and put it in the root of your SD card.
2-Turn off your phone, press the volume up and power button and hold both until vibration.
3 - In the menu that appears you will have:
"select boot mode:
volume_up to select. volume_down is OK
Normal mode "
4 - Select "Recovery Mode"
and press volume - (move with volume + and validate with volume -)
5 - You have an image, press the "home" button (the one in the middle)
6 - Move to "apply update from sdcard"
(move with the volume + / -). Confirm with the "menu" button (the right one)
7 - Select the desired file on your SD card and press the "menu" button
8 - Wait until the operation finish and restart by selecting "reboot system now"
9 - wait till your device restart normally ...
Acer Z2 sdUpdate
I hope to provide information necessary for handling.
please inform us the result.