Life on FR4

I get myself intro repairing Xbox One Controllers. I going to write some of my experience about repairing this thinks. Most common problem is the analog stick of course, moving part are the weakest point of any device. You can buy a replacement part for a few buck, but actually you need only the variable resistor part. You can clearly see what is going wrong here, the conductor layer are broked on the left green resistor. If you want cheap fix this stick you should only replace the faulty resistor. Disassembled analog stick Another common failure is the board-to-board connector.You can find 2 different pcb inside the controller which are connected by this way.The problem come up when the solder joints cracks.This is because the upper pcb get different kind of forces under in use. The solder joints give up and crack and can't conduct any more. Broken connector I attached more example here. Angry player XD And here is an interesting thing for the end: I tested out