820-3476 Camera not detected

[phuketmymac]

Hello,

We have that board which won't detect a camera.
We have tried a known good display and same result.

I did test in diode mode the camera connector with the camera plugged and not plugged and compared it with a known working board.
Here are the results:

0	0		0	0
0.37	0.367		0.353	0.355
0.37	0.367		0.353	0.355
0	0		0	0
0.37	0.367		0.353	0.355
0.365	0.367		0.353	0.355
0	0		0	0
0.496	0.479		0.456	0.453
0.496	0.479		0.472	0.468
0.69	0.69		0.387	0.39
0.69	0.69		0.387	0.39
0.392	0.38		0.403	0.38
Good	Bad		Good	Bad
Without the camera plugged	with the camera plugged in

The top one is the first pin of connector.

I did also check the connector under the microscope and it looks clean.
I've replaced the 2 filters L4007 and L4009.

The board already had been fixed for liquid damage from U8330 down to U7100.

Any hint of this specific problem?
Where should look now please?

 

[rvanpruissen]

I don't know by heart which voltage needs to go to the camera, but did you check if it's getting power?

 

[dukefawks]

U3900 is a common problem. Trust me you rather not mess with that one, just live with no camera.

 

[phuketmymac]

Camera is getting power yes.
I did already ordered some replacement U3900 chips from eBay with solder balls.
I will replace the chip and see what happens.

MacBook without a camera... OMG! (customer would think...)
Have to try to fix it.