Chosen Solution
do I need all ports, the screen does not turn on after fitting the ribbons to the correct ports
That’s because the third flat cable doesn’t strictly belong to the screen assembly as it can be relatively easy swapped from the broken screen to the new one. That’s including the front camera, ear piece, proximity sensor and ambient light sensor. Here’s the guide for the replacement: iPhone 6s Front-Facing Camera and Sensor Assembly Replacement
