820-3435-B MacBook Air no backlight

[Sr. Robot]

Hello, i have a 820-3435 with no backlight. It shows very small signs of liquid damage.

1. Fuse was blown, after replacing it blew again. One side of the fuse mesures 1.1v and the other 8.5v

2. U7701 balls do not appear to be corroded.

3. Thers continuity from fuse to Q7706. Theres also continuity from Q7706 to L7701

 

[2informaticos]

Post diode mode to ground on both pins of D7701; w/ and w/o LCD connected.

 

[Sr. Robot]

Without LCD:

Pin 1: 0.512v / Pin 2: 0.375 v

With LCD:

Pin 1: 0v / Pin 2: 0.376 v

 

[2informaticos]

Please, check again and use schematic notations (A/K), instead of boardview.
LCD connection cannot short A pin to ground!
If you get short at K pin with LCD connected, then change LCD assembly.

 

[Sr. Robot]

Sorry, again:

Without LCD:

A pin: 0.376 / K pin: 0.512

With LCD:

A pin: 0.376 / K pin: 0 v

 

[2informaticos]

As I said...
"If you get short at K pin with LCD connected, then change LCD assembly."

Just in case, be sure the short is not caused by bad video cable, when inserted in the connector.