so i recently updated my nexus 7 and it became "bricked" i can access the boot loader menu but when i try and start i get booting failed. i downloaded root toolkit in an attempt to fix i and when i go to unlock the bootloader everything works fine i click unlock but then when i go to restart the bootloader it never turns back on. i will leave it for hours and get nothing. I feel like this is the last thing i need to figutre out to fix it. so anybody knows how to get the restart bootloader button in the menu working again please help me out.