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Old 01-20-2018, 06:32 PM   #1
m4a2t0t
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Default A1286 No backlight

I have a Macbook Pro A1286 with a core i5 and it has no backlight after reballing the GPU.

The laptop would not display any high resolution content. After clicking on the username the laptop would start loading and then display a grey screen. It would not load recovery, internet recovery or any utility.

The laptop will now login and displays content fine but it has no backlight.

Any suggestions on what to look at first? Anyone have schematics or board viewer?

I've tried re-plugging all the cables, SMC reset and tried the brightness buttons. Anything I might be overlooking?

Thanks

EDIT: FOund board viewer https://www.badcaps.net/forum/showthread.php?t=44413 . Will check Backlight filter.
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Last edited by m4a2t0t; 01-20-2018 at 08:01 PM.. Reason: Found board viewer
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Old 01-21-2018, 12:40 AM   #2
audiomodder
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Default Re: A1286 No backlight

Search 820-2915-A schems and boardview in an internet search. you will come up with stuff.
Did you seriously attempt a GPU reball without even the schematic? Wow....gutsy.
Once you get the schem, check out the backlight driver circuit and look at the EN pin. Also, the CLK and DATA (coming from the GPU) lines with 100k pullups to the LVDS are important and will keep your internal display from working if they are shorted or missing.

There is also a small backlight fuse which is always worth checking. But get on those schematics first.
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Old 01-21-2018, 07:09 AM   #3
alihomee
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Default Re: A1286 No backlight

u can find fuse and light ic near the fan connector
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Old 01-21-2018, 02:11 PM   #4
m4a2t0t
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Default Re: A1286 No backlight

Thanks. The fuse is open. Guess I should start at the beginning of the circuit instead of the end.
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Old 01-21-2018, 11:13 PM   #5
audiomodder
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Default Re: A1286 No backlight

yep, check the EN stuff first, then the IC output, then both sides of fuse. If all is OK only THEN replace the fuse.
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