I've accidentally broke my laptop keyboard backlight ribbon cable when disassembling my laptop. I want to solder it back by patching with copper wires or maybe copper plates.
My question is, it is a 4-pin connector, i exposed the end of the ribbon with sand paper but there is only 2 lanes of copper instead of 4. Do I just need to solder them back or it should be 4 ? I found the diagram of the keyboard light and attached some photos of my cable.
Best Answer
The schematic shows a connector with 4 pins and 2 grounding tabs. It shoes pin 1 and 2 are ground, pin 3 and 4 power. The FPC has two conductors, 2 pins per conductor to increase the amount of copper that is carrying the power and return path of ground, likely to reduce resistance and power loss. It's exactly how it's supposed to be.
If you broke the fpc, simply repairing it by reconnecting each conductor to where it should be connected is the only method.