No front or back camera black unresponsive digitizer

You have more than likely damaged a componant that sits around the lcd connecrors remove the black tape covering them and inspect

What brought the unit to a point of disrepair? If it has been dropped or thrown against a wall (ala my daughter's creative way of getting rid of a boyfriend), the motherboard may have sustained some damage. Go through each and every connector and ensure a good seat and no damaged connectors. My concern is the blank digitizer in relation to everything else. It could be as simple as a bad digitizer and as complex as a motherboard problem. But thouroughly check all connections before forking out anymore money on the unit. Hint: If the digitizer is good, it should respond when you connect the battery and press the power button for 3 seconds. If the unit isn't powering on at all, your charging module and/or your motherboard are the likely culprits. Best of luck and hopefully a successful, non-expensive solution to your repair.