My mothers a500 is stuck on the lock screen and will not respond to touch commands. Also if I try to hold the power button it just restarts and goes back to the lock screen. If I hold the power button and the volume up button it sais clearing cache and something about opening the unzip.zip from the sd card. Iv'e also tried the reset button and it just boots back to the lock screen too. I have a micro SD card and I'm wondering if I can reinstall the OS from that and get this thing working again. I'm not worried about losing any data I just want to get this working again for my mother. I have no experience with tablets but if someone can just walk me though step by step with the download links of what I need on the SD card I would appreciate it very much.