820-01521

Mac Tech

Member
Hi everyone.

This macbook does not work the keyboard illuminator, I see that in the system preferences it does not detect it.

I tried another plate of the same model 820-01521 in the case and if it is detected by the lighting in the system preferences and when I press the keys it lowers and raises the lighting without problem.

So I know it's a motherboard problem.

In the J6700 connector I made measurements of the Diode with the good board and I only have two altered values

"PDM_DMIC_DATA0_ISOL"
"PDM_DMIC_DATA1_ISOL"

I think this is from the microphone, I tried it and the microphone works.

PP5V_G3S_IPD_F : 5.1v

PP3V3_G3H_IPD_F: 3.3v

PP3V3_G3S_IPD_F: 3.3v

Am I forgetting something?
 

2informaticos

Administrator
Staff member
ALS is associated with webcam; both have the same power rail, 5V_ALSCAM.
And KB backlight cannot work if ALS doesn't work.
Check first 5V presence at C8577; is the webcam working?
Also check if LCD backlight varies when you direct flashlight on the webcam.
 

Mac Tech

Member
you mean the ambient light sensor, ok when covering the camera on the screen with your finger or hand, it does not show brightness either.
 

2informaticos

Administrator
Staff member
You didn't understand me.
When you put more, or less light on webcam (ALS), LCD backlight should be automatically adjusted.
If not, you have a problem with ALS (on MLB); of course, KB backlight will be disabled in such case.
 

Mac Tech

Member
ok I did the following test, put the functional board and put the iphone light on the camera and turn off the brightness of the keyboard, the board that I am repairing does not do the same, then the ALS is damaged, then where is the integrated one that controls ? T2? because 1.8v voltages go to T2
 

2informaticos

Administrator
Staff member
I said to check LCD (screen) brightness reaction.
You have a problem with KB backlight, can't use it for test; as you never get it on.
 
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