I have an iPad 3 WiFi version which was jailbreak-ed on ios 7.1.x a couple of months back. Yesterday i wanted to upgrade it to the another version, so downloaded the iPad3,1_8.1.2_12B440_Restore.ipsw form this website(iphonehacks.com) and tried to do a manual upgrade on the iPad3 using shift key+update button on iTunes. Since it was jail broken the OTA upgrade method was not possible.(Correct me if i am wrong). Also, just an heads-up i am very new to all this would require your support.
Unfortunately, in a hurry forgot to keep the backup of the iPad while upgrading. The process didn't worked well and now the iPad is showing symbol of USB cable and iTunes with an error message on iTunes "3194". I tried to put the ipad in DFU mode(did some research on net and YouTube and thought that this would solve the problem but failed) to initiate the manual process for upgrading and restoring the iPad with the same file iPad3,1_8.1.2_12B440_Restore.ipsw. Please help i need this device up and running.