A1466 820-00165-A no backlight

[hgoncalves]

Hi,

I have an A1466 820-00165-A that has no backlight.

Already replace U7701, but with no success.

I get 8.6V on F7700 and 8.6V on D7701, but no backlight.
I get 3.3V on R7757 BKL_SDA
I get 3.3V on R7753 BKL_SCL
I get 2.8V on R7715 BKL_EN
All return resistance seams to be ok.
Can it be feedback? How to be sure?

Can you help?

 

[2informaticos]

I suppose you already check to confirm image is present.
It should be, as you get 8.6V at D7701.

Did you check XW7720 bridge continuity?
What about BKL_PWM level?

 

[hgoncalves]

HI,
I do have image, but i didn't checked XW7720 nor BKL_PWM...

On BKL_PWM i have 1.46V

How can i measure XW7720 bridge continuity?

P.S. PPVOUT_SW_LCDBKLT_FB test point (near D7701) seams to be corroded.

 

[2informaticos]

Some ideas here...

 

[hgoncalves]

It seams that i don't have XW7720 bridge continuity

 

[2informaticos]

You have the solution in the second picture; if is not possible to solve it like in first pic.

 

[hgoncalves]

Tks. It worked!