Try Disconnecting the battery from the logicboard, drain the excess power by holding the power button for 15-20 seconds. Try this while 3 cables from the screen still intact.
*After draining the excess power put the cable intact in the logic board and try to hold Home button for 3 seconds followed by Power button (don’t let go until the logo comes up). Reply me the feedback if it works or not.
When reassembled, the screen may not turn on. Try fixing this by draining the power through disconnecting battery, and holding down the power button for 15- 20 seconds. This fix works for me I got frustrated at the point that it won’t turn on at first.
