In this post I briefly document document of pinout of Lenovo Thinkpad webcam FRU 04X5729 and how to reuse it, in case you stripped one from a broken laptop display.
This webcam is attached to the wiring inside the display by a small connector with seven pins. Three of them are used to connect the microphones (the small golden circles at the left and right side in the image above). The remaining four are wired to the USB interface of the camera sensor. The table below describes the pinout counted from right to left if the camera is front-facing like in the picture above (thus: from the inside to the outside).
| Pin | Description | USB Wire Color |
|---|---|---|
| 1 | Unknown | |
| 2 | Unknown | |
| 3 | Unknown | |
| 4 | GND | black |
| 5 | D+ | green |
| 6 | D- | white |
| 7 | VBUS (3,3V) | red |
The webcam itself operates at a voltage of 3,3V, while external USB devices have an operating voltage of 5V. Using a step-down converter or linear voltage regulator to reduce the USB supply voltage to 3,3V would be the clean solution. However, the voltage drop of two simple silicon rectifier diodes (e.g. 1N400x familiy) added in series to VBUS is also sufficient in my experience.
It is quite difficult to solder a wire directly to the PCB. There are test points beyond the connector, one for each pin. Yet, they are pretty weak so if you manage to solder a wire to them, they may easily be stripped off the PCB. An approach which worked better for me was to carefully pry away the upper plastic part of the connector. This way, it is possible get good access to the contact pins of the connector. By bending them a bit upwards and away from each other, one can get enough clearance to solder a wire to each of them. Since this is still pretty fragile, it is a good idea to generously add some hot glue after performing a first function test.
