You can download firmware 101b platinum from here update.archos.com/AFMv1/storage//files/full/ac101bpl/20140812.191729/update-allwinner.zip
Then copy that on root sd card.
Run tablet in recovery mode vol - and power.
First clear cache then one more time cleare cache.
now start update form external memory.
Tested i have unbrick from boot loop my archos 101b platinum.
I've unbrick my tablet empty cache and data from recovery menu, but the tablet is limited like in a demo mode: no settings menu.
If i try tu update it using the update-allwinner.zip fails to verify whole-file signature.
If i try to use adb shell i received: exec '/system/bin/sh' failed: No such file or directory (2)
The solution seems to be to reinstall the rom, but i can't do it because the system/bin is partial.
Do someone have any idea?