Macbook Air A1466 no backlight no image

[imcool]

Hello,
On this Macbook Air A1466 with 820-00165
I have only 8V on backlight line but no high voltage in boost circuit, I have checked all components like caps and diode and they seems to be ok.

I have noticed that when macbook chimes after turning on there is no image at all even with flash light,

I have tried 2 different OEM LCD and still there is no image,
I see the LCD fades out when i remove power or turn off the macbook.

I have 2 problems
1 No image
2 No backlight, but i have 8VDC on backlight circuit.

I have checked and verified the lcd connector diode mode values with working macbook air and they are exact same.

I am not sure how to proceed on this or its some other issue and I am wasting time on fixing backlight.

Can someone with their experience help me out please.
Thank you so much

[zpi]

Re: Macbook Air A1466 no backlight no image

Hey, easy. If you want some sort of output (in this situation backlight) just check enable signals check bklt_en and bklt_pwm signals on board, then you will know if board wants to turn on backlight

[imcool]

Re: Macbook Air A1466 no backlight no image

Hey, easy. If you want some sort of output (in this situation backlight) just check enable signals check bklt_en and bklt_pwm signals on board, then you will know if board wants to turn on backlight

thx so much for replying

can the two lines you mentioned abive cause no image as well?

[zpi]

Re: Macbook Air A1466 no backlight no image

No, first lets check if these signals are present, if they are. Then we need to fix bklt circuit, maybe there is an image, you just cant see somehow. Because when you turn off macbook, you said that lcd fades out, that means, that lcd is getting power is recognized and should show something.