[SOLVED]Camera proximity causes several sensors to fail

[Sykulski]

After wasting time to figure this out I thought I would share. It's a MBA13 - 820-3437. I had 4 sensors failing: "CPU Proximity", "Charger Proximity", "S2 Camera Proximity" and "Input Air Flow". Machine running slow with full speed fan. I wasted time checking all these sensors just to find out everything looking normal. Then I tried making the sensor test without camera cable connected. And guess what... All sensor errors are gone! When I connect camera cable the 4 sensors fail again. So remember this next time you have weird sensor problems - disconnect camera before you go spending time on troubleshooting other sensors Also "S2 Camera Proximity" sensor stops failing when cable for the camera is unplugged

 

[larossmann]

You'll see in the schematic that the ALS connector is on the same data line as the other sensors. If you measure with an oscilloscope on the pullup resistors for that data line with the bad webcam/webcam cable plugged in you'll see it only goes up to 2.6v instead of 3.42v, check it.

 

[Sykulski]

Thanks. I checked and you're right. I just removed pin 8 and 9 from the ALS connector and now machine runs fine. Only light sensor capability missing but the customer doesn't care about that. Thanks again.