820-01958 no keyboard light

Levitor

New member
Hi I have macbook Air 2020 motherboard 820-01958 the keyboard light does not turn on and the laptop does not sleep when closing the lcd and no longer turns on when opening the laptop. the problem started when i was changing the lcd, i connected the lcd without disconnecting the battery. he broke a coil, and cut some tracks, I see that it is difficult to find the brd, if someone has one on the bench, he could help with the trails.
I need see probe points near U6500 besides lcd connector.
Thanks
 

2informaticos

Administrator
Staff member
Probably webcam not working, supposing is the 5V ALSCAM rail (L8570).
That means ALS is also not powered; good reason for non working keyboard backlight.
 

2informaticos

Administrator
Staff member
When you have a problem with Ambient Light Sensor (ALS), the keyboard backlight doesn't work in such case.
Check traces for ALS to LCD connector.
 
Last edited:

Levitor

New member
I can’t check traces because I don’t have other motherboard to copy. Do you have one to help see continuity with multimeter?
 

2informaticos

Administrator
Staff member
Pins 34 & 36 of J8500 go to resistors R8555/56 (33 ohm).
You should find them.

Start checking diode mode to ground on both lines.
 

2informaticos

Administrator
Staff member
Yeah, sorry for mistyping.

You should get the same diode mode reading on both lines; I didn't ask for short.
And check their continuity with J8500.
 

2informaticos

Administrator
Staff member
"You should get the same diode mode reading on both lines; I didn't ask for short."
Can we get the exact readings???
 
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