Sometime ago my old Asus X101H netbook died with a molten cooler fan. I've extracted it's webcam, which I want to use for another project.

Now I'm trying to map the pinout of the connector. The situation looks like this:

The boards front

The boards back


So I'm guessing it's using USB to connect the webcam. On the board is also a microphone, so I'm guessing there are two USB interfaces.

I've figured out the grounds by measuring the resistance by the screw hole (left side of the boards frontal view).

The black and the blue wire are GNDs. I know it's hard to figure out D- and D+ but it's not so bad if I get the wrong.

My only problem is, how can I figure out which pins are the VCCs?

On the label of the cable is written:

P/N: 14004-00090100
HIGH-TEK (KW5) 11/08/22

I've a Fluke Multimeter, but not many other tools.

Thank you in advance!

  • \$\begingroup\$ Practically speaking, you probably do not. If you really want to pursue this, first you'll need to boot the original system with this connected and figure out if it is showing relevant USB devices. It's somewhat likely this is not USB but rather some synchronous interface - if you can't run the original system with an external fan pointed at the CPU you'd probably need a scope to tell. If you want something for a project, buy something with known specs. \$\endgroup\$ – Chris Stratton Jan 19 '19 at 18:35
  • \$\begingroup\$ Thank you for your comment. Well, there is no way to get the original system back together. I've found block diagrams of other ASUS EEE netbooks and most of them connect the camera via USB. \$\endgroup\$ – Robin Jan 19 '19 at 18:46
  • \$\begingroup\$ You should be able to figure out power and ground. If you want to take risks with a sacrificial USB hub and sacrificial computer, you could then experiment with data line candidates and see if there is a combination that works. But only if you are willing to accept a slight but real risk of losing everything involved in the experiment. Basic webcams with USB connectors sell for a few dollars... \$\endgroup\$ – Chris Stratton Jan 19 '19 at 18:51
  • \$\begingroup\$ Your best bet might be to start doing some reverse-engineering of the circuitboard. See what's connected to what, and see if you can find part numbers. I doubt you're going to figure it out though. \$\endgroup\$ – Hearth Jan 19 '19 at 19:23
  • \$\begingroup\$ Be aware that schematics for your computer appear to be available online and depending where you live it may be perfectly legal for you to download it temporarily for educational purposes. You should be able to find both precise pinout and the names of connected chips there. \$\endgroup\$ – K H Jan 19 '19 at 21:40

It's very likely your webcam board runs from 3.3V and not the usb standard of 5V. With that in mind, the simplest way to find the VCC pins is to look for decoupling capacitors, and LEDs. The larger capacitors on your board will be connected between ground and a power rail. That might be a local chip generated power rail, in which case move on, or it might be the input power from the connector, in which case you have a winner. Again with the LEDs the +ve side of the LED will likely either be connected to a +ve power rail, or connected through a resistor to a +ve power rail.

I'd expect the microphone to be analogue rather than USB, so you can expect 2 of 3 wires for that, a bias supply a ground and a signal line, or just ground and signal and bias joined. They might generate the bias supply on that board from the 3.3v, but it's unlikely as that digital power supply will be noisy, and they'll already be a bias supply on the motherboard for the microphone socket. If the designer was competent they'd probably keep that away from the USB end of the connector. You can likely find the microphone by measuring continuity from its pins.

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