No backlight on MacBook Air 2015 820-00165

[razorwoods]

Working on a MacBook Air 2015 820-00165 that had minor liquid damage. It's not displaying any backlight. The machine fully boots and does display an image.

On Q7706 I'm seeing:
PIN 4 - 8.5V
PIN 3 - 8.5V that switches to 3V while booting
PIN 1,2,5,6 - 8.5V

Suggestions ?

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[aprendiz]

Voltage on pin 3-4 and 18-19 from J8300???

 

[razorwoods]

J8300 has:
PIN 3 - 8.5v
PIN 4 - 8.5v
PIN 18 - 3.29v
PIN 19 - 3.29v

 

[aprendiz]

It is not boosting, BKL_EN present??? Also check feedback trace from Cathode of D7701 to ball A5 from U7701...