Resetting your Acer A500 tabletHolding Volume UP, Turn on Power, then switch Lock On/Off back and forth with Volume Up Continually held. THIS STARTS THE RESET, wait for 20 sec. to start Android.
You may have to perform a reset if your tablet fails to respond when buttons are pressed or the screen is tapped.
To reset your tablet use a small thin object (such as a paperclip) to press the recessed reset button.
Insert a small thin object (such as a paperclip) to reset power to the tablet.
ACER Iconia Tab A500 Clean boot
A clean boot will restore your tablet to the factory settings.
Warning! This will erase all your personal information, any contacts stored on your
tablet and any programs you installed.
Open Settings from the application menu, then tap Privacy > Factory data reset; click Reset tablet and then Erase everything to format your tablet.
After a certain number of wrong entries, you will be presented with an option to reset your pattern. Tap Forgot pattern? and enter your google
account username and password.
Note: You must have an active Google account on the tablet. If not working do a clean boot.
How to Install any iconia A500 patch
Install an update.zip file on your Iconia A500 tablet check acer website here
1. First copy update.zip file to your FAT or FAT32 microSD card.
2. Copy Update.zip to the microSD card, but delete everything else on the card.
3. Power off your fully charged A500 tablet with the microSd card inserted.
4. Press and hold the Volume Down key then press and hold the Power key together.
5. When you see the LED turns on, release Power key but still hold Volume down key.
The Acer logo will appear on the screen and the tablet will vibrate.
Still press Volume Down key until you see "Erasing cache before SD update..." message.
The update.zip file will be automatically installed and then your tablet will reboot.
A500 system update: Select Apps, Settings, About Tablet, and System Update.