Chosen Solution

replaced the touch + lcd. there is no visual at all, the phone does turn on because it makes a noise when charged or connected to the computer. i have looked through the internet and i havent damgaged the gold pin at the top of the logic board. i had one lcd in, and i unplugged the connectors and plugged another lcd in.. this worked! so there must be something interferring, any ideas anyone???

When you connect the LCD/Digitiser connections to the logic board, are they both at even lengths? (see images below)

When installing the digitiser assembly it is crucial that these are in line with each other or they will rip when you try to connect them to the logic board. Sometimes they can get stuck in the slit when you insert them into the iPhone chassis and can cause this issue. This exact issue happened to me, i had screwed the screen into the chassis and just as i was about to connect it to the logic board i realised one was short. In my ignorance i tried to pull it free but ended up tearing the LCD cable rendering the entire part useless. Look for any tears in the Digitiser/LCD cables, if any are found then that is your issue and you will need to buy a replacement :( Hope this helps!