I use my tablet 3g only with wifi mode in last 3 moths, but one day, after some replacing apps, and reboot de tablet. The keys were locked

and didn´t allow to do nothing without sim card. Now I know, that was replacing hangouts for talk.

I  started recovery mode but I haven´t a backup, and in the advance option push " Wipe dalvik cache", and another wipe options.

At last, I decide to reinstall all, and conect the table to the pc. First erased system, boot and recovery with fastboot erase comand,

and reinstall "ext4" with the firmware rev14 archos arnova 7cg2 (the same I had before the accident), and something went wrong,

I couldn´t use this option, because the tablet stopped in arnova screen, and don´t continue, and in the recovery mode (using comand

adb reboot recovery) appears e: can`t mount cache recovery log.

But If was possible to install and boot the "NO SD" files, that I´m using actually.

¿could anyone explain to me what I damaged, using wipe dalvik cache? ¿ And could I repair to reinstall ext-2 or ext-4 mode?