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Procesador Intel Core i7 de cuatro núcleos a 2,2 GHz (Turbo Boost de hasta 3,4 GHz) o 2,5 GHz (Turbo Boost de hasta 3,7 GHz) con 6 MB de caché L3 compartida.

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lcd backlight doesn't work. after water.

Hi!

After water lcd backlight doesn't. I think fuse is broken or led driver failed, but i don't know where it is. I don't have schematic. Could somebody help me?

I have skill in soldering and have expirience in electronic repair.

Thanks!

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The fuse never dies on 820-3787 so don't waste the time, effort, fuse, or solder following that advice. This is a "smart" circuit that turns power off after Q7706 if it senses a short based on current sensing resistor R7700 which can be determined from 2 seconds of looking at page 62 of the schematic.

Measure for short to ground on C7719 on PPVOUT_S0_LCDBKLT side. Multimeter in diode mode, black probe on PPVOUT_S0_LCDBKLT side of C7719, red probe on a screwhole. What do you get? Now remove the LCD cable from the board and make the same measurement. What do you get?

What does pin 1 of the LCD connector look like?

If there is no short to ground, turn it on. What voltage do you get on the source of Q7706? The drain of Q7706? The PPVOUT_S0_LCDBKLT side of C7719? Pin 1 of the LCD connector?

What voltage does R7742 have on each side of it?

I say it is &&^&@@ up LCD or burned LCD connector that is the culprit here which won't even need a schematic or a boardview to diagnose, just eyes and brains. On the newest retina, the backlight fuse is that LCD connector that they foolishly think will work through a fault state with only one &&^&^$^ pin; such arrogance is commonplace with Apple product engineering. One step forward, two steps back. Let's go through the effort of adding high side current sensing to the backlight circuit only to end it with two less pieces of metal passing current than what we used seven years ago...

Either way, find a schematic & boardview for 820-3787 online, there's no shortage of Russian websites that love selling this $@$*.

P.S.

If you bought this without a discrete GPU you have an 820-3662 board for which there is no released schematic or boardview, so with that board you have to reverse engineer it yourself. Good luck if that is the case.

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Hey,

I got a burnt lvds connector on display side on the same macbook pro, the very left pins of the cable look burnd an on the little bord connected to the display as well. Is there a chance to fix that? Would only a display replacment help or is there certainly more damage? Thanks.

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I would recommend carefully cleaning the board with isopropyl alcohol and you will most likely have to replace the backlight fuse. (DO NOT JUMP IT) it a fuse for a reason. If that doesn't work i would recommend purchasing a schematic and going much deeper into the backlight circuit. Good Luck!!

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