Macbook A1466 820-3437 Light Issue

[Instafixx]

Hello,
The Macbook turns on but no backlight (Confirmed by a torch that the display is on). The board is clean but found a little bit green beside L7701 but no component seems affected or shorted.
Getting 8.5V on the both sides of L7701.

Is it the feedback trace issue that ll require a jumper or is it something else? How can i verify ?

 

[2informaticos]

Inspect XW7720 bridge.
If needed, fix it.

XW7720.rar

drive.google.com

 

[Instafixx]

I dont undertand. Can you please guide me ? What exactly do i check ?

 

[2informaticos]

Look at the pics.
You can see damaged connection there; figured with red line.
Is your case?

 

[Instafixx]

The XW7720 point was green. Cleaned that area. Diode Mode Reading to Ground is 0.618 (Red to Ground)

 

[2informaticos]

Do you have continuity where the red line?

 

[Instafixx]

Continuity between which 2 points? One is the point marked in red and the other ?

 

[2informaticos]

There is a red line, not point!
It marks the bridge trace which usually gets corroded.

Look at schematic, to understand what connection to check.

 

[Instafixx]

There was no continuity . Ran a Jumper Wire. But still the same.

 

[2informaticos]

You should check the continuity on the other side of the board.
I'm pretty sure the trace inside the board is broken.
One boardview screenshot shows you how to run the wire.
Scratch the trace near the U7701 corner; do not touch its corresponding ball with solder iron.

Just in case, check first if there is continuity.

 

[Instafixx]

Did that too but still no light. LCD is good. Checked that

 

[2informaticos]

You may need to change U7701 too.
It may have corroded balls..

 

[Instafixx]

Bang On. Its done. Thanks