Samsung Galaxy Tab 2 7.0 GT-P3100 Stock firmware flash file.

1. Download and install Android command line tools for ADB.
2. Connect tablet to USB, enable USB debugging in Developer Options.
3. Ensure device is listed in with command adb devices.
4. Download firmware for Android 4.2.1 or 4.0.3.
5. Download Odin Downloader for writing firmware v3.11.1.
6. Enable root access with command adb root.
7. Switch to download mode with adb reboot download.
8. Open Odin and ensure device is added in Log.
9. Select AP and choose path of firmware .tar.md5 file.
10. Once its ready, select Start.

References

• Samsung Galaxy Tab 2 7.0 GT-P3100 Stock Firmware :: Firmware Panda
• Samsung Galaxy Tab 2 7.0 P3100 Recovery Mode and Download Mode
• Download Mode SAMSUNG P3100 Galaxy Tab 2 7.0 :: HardReset.info
• not able to get into download mode for galaxy tab 2 7.0 P3100 :: XDA Developers
• How to use Odin Downloader :: Odin Downloader