Long screw damage by definition is when a technician tries to fit a screw that is too long into the wrong screw hole. It usually occurs during a screen replacement. The screw will dig into the different layers of the motherboard and sever traces. When this happens, the way to fix is to attach jumper wires that reconnect the severed lines. In this case, 5 different lines were broken causing image to not be displayed even though the phone was powering on. Had the screen been functioning, then it would have been clear that the camera and the ambient light sensor were also not working because of severed lines.
Here is the initial inspection with the screw post having been removed by the previous technician:
Step 1: Shave down to second layer to reveal traces:
Shave a bit further and you can see the broken traces:
This is what we should see:
These are the lines that need to be fixed:
Start by adding the 1st jumper using .009mm superfine silver wire, tack it down with solder mask:
2nd Jumper:
3rd Jumper and things are getting cramped:
Apply more solder mask to protect your wires and continue to next jumper:
If you are curious how small these lines are, here is a comparison to my pointer finger:
The final broken line appears to be in tact (AP_TO_LCM_RESET_L). However, upon measuring resistance it is clear that this line has also been disconnected. Measuring the via gives a good resistance so I decide to jump from the via all the way to the filter it is supposed to connect to:
Finish up by completely protecting your wires:
We have a working phone!
