Here you can download stock firmware for your Lenovo Ideatab a3000. This is available for free to download. You can download it using links provided at the end of this post. The Firmware flash file is based on Android 4.2. You can flash it using flash tool on your computer. To flash this firmware on your Lenovo Ideatab a3000 you need USB driver and Flash tool. if you don't have USB driver and flash tool then no need to worry about. because Flash tool, USB driver is available inside this firmware zip folder.
if you don't know how to flash lenovo idea Tab using SP Flash Tool then you will find instruction manual inside download package.
This downloading package contains flash tool and usb driver for your lenovo idea tab, so no need to search anywhere to download them. Please, take backup of personal data from your phone before flashing. After flashing you will lose all your data from phone memory. Get Firmware