Hi so I attempted and failed at rooting my Samsung Galaxy Tab 4 7.0 I must have downloaded the wrong file or something because I got a screen that said "firmware download encountered an error..." Now it wont re-boot or do anything. So that's problem one. Problem two is when I was adviced to put the original firmware back on I realized none of my computers USB will acknowledge the Tab 4. Also when I plugged in my phone Galaxy iii it wasnt being acknoweldged either. I tried different cord and it didnt work. I also plugged in a friend phone and it works just fine. Help me.....