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Re: Macbook pro a1286 no backlight
Hello,
We replaced the resistor and see that now the Display is also not there.
So we just removed the mosfet wire to ground that we did and now everything is working fine. It is kept under observation. I have no idea how and why did it happen.Comment
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Re: Macbook pro a1286 no backlight
If it is now working this means the bottom 2 x MOSFETs are enabling ok. Only if they are ON, then the voltage divider is created to turn on the top mosfet.
Perhaps a good idea to flux and reflow the bottom 2 x mosfets. If you lose the display, check the gate voltage of the bottom 2 x mosfets.Comment
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Hi everyone.
I hope someone has some suggestions on how to proceed with this issue.
I have an Apple A1286 2012 MacBook Pro with 820-3330 Logic board. My customer purchased this from me in full working condition. Unfortunately, it overheated on him due to being left running on his bed.
Investigation showed the LCD Backlight was not working (had a latent image and external monitor worked), the battery was no longer functioning (system couldn't read it or charge it) and the Samsung 850 EVO SSD was dead (not seen by finder or disk utility). Quite the trifecta.... -
Hello all,
Am trying to figure out this backlight issue with this A1990 Macbook Pro.
Tests performed:
There is no backlight even with a good screen.
Backlight IC is receiving the correct support voltages.
Fuse F8400 ok
Current sense resistor R8400 ok
Backlight IC is receiving 3.3V on enable pin.
Backlight IC receiving voltage from PPBUS_G3H, aprox 12.5V.
Backlight IC receiving 5V from PP5V_G3S
Backlight IC BKLT_SCL and BKLT_SDA both measure 0.545V diode mode to ground
I2C_BKLT_SCL and I2C_BKLT_SDA both measure... -
Hi all
I have a Macbook Pro A2442 with the 820-02098 from a friend which has no picture on the display, however, the backlight works.
He was streaming a football match on a questionable site, then the site crashed, and the problem emerged.
Initially, he sent it to apple, who quoted him £1323.95 to replace the display, lid angle sensor and top case.
Obviously, he decided against this and gave it to me so that I could have a crack at it.
From initial diagnostics, I connected to an external monitor, I first tried with a HP 22W monitor, and I booted into the boot menu... -
Hello Everyone,
I'm looking at purchasing a used LCD from ebay for my macbook A1990 2018 15inch which LCD I cracked. Since new / used but working displays cost around 500$ , I found a Grade A+ LCD display for A1990 which has a good price of 110$ but has no backlight.
I would need just to make sure that what I know/my reasoning is correct:
- No backlight means flexgate issue, therefore changingthe flexcable would be enough (I can microsolder to fix the flexgate problem, done it a few times already)
- Seller confirmed its a LCD issue, and not an issue with the... -
Hi guys, I've got MacBook Air a2337 with no backlight. Once while testing it displayed with the backlight, however after restart problem come back.
The laptop was tested with fully working screen.
PP5v_BKLT_A/B 5V
PP5v_BKLT_D 5V
PP5V_S2 5V
PP5V_SW_LCD 0.4V
P5VS2_PWR_EN 1.8V
P5VS2_BST_R 8V
P5VS2_SW 5V
PPBUS_5VS2_VIN 5V
PPVOUT_LCDBKLT - Doesn't short 0V
FP800 - Both sides 12v
BKLT_EN_R & BL_PWR_EN - around 1.8v
LP800 0.014V On both sides (should be 12? / no short)
UC300 & UP800 Replaced...
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