Once you downloaded the firmware, we can downgrade your iPad to 7.1.2 version
Hi Ashik. I did the reset and it made no difference. I've downloaded the firmware file on the iMac, what do i do next please?
Open iTunes application on your computer
On your iPad Press and hold the Home button and the Power button at the same time.
After EXACTLY 8 seconds release the Power button. Continue holding the home button until your iTunes shows a message telling you that it has detected an iPad in recovery mode.
Now, hold down Option key on your keyboard and click Restore button. This will ask you to select the firmware file. Select the file you've downloaded. Click OK
Your iPad will be restored now to older version.