Dear friends from badcaps.net!!
May I request some piece of advice for a Macbook Air 2015 820-00165 motherboard, waterdamaged, with no backlight....
I have cleaned the board in the ultrasonic bath, then investigate its electronics. The Macbook boots up, chimes, displays the log in screen and, after cleaning the keyboard is responsive. There is no backlight and its circuit voltage, measured at the connector, diode and output capacitors is 8.20v. The BKL EN resistor R7731 was burnt and desoldered. I have replaced it and the BKL EN line shows 2.8v... but the backlight output is always at 8,20v. The fuse, the diode are good. The vin is at 5.20v. The grounds are good. All the voltages around the backlight IC are good: SCLK, SDA at 3.3v except the PWM which is between 0.9 and 1.5v. I have changed the backlight IC, LP8550, new and original three times with still the same result: no backlight and still, 8.5v on its line....
What can I do more or should I change the board?????
Thanks for your advices!!!
May I request some piece of advice for a Macbook Air 2015 820-00165 motherboard, waterdamaged, with no backlight....
I have cleaned the board in the ultrasonic bath, then investigate its electronics. The Macbook boots up, chimes, displays the log in screen and, after cleaning the keyboard is responsive. There is no backlight and its circuit voltage, measured at the connector, diode and output capacitors is 8.20v. The BKL EN resistor R7731 was burnt and desoldered. I have replaced it and the BKL EN line shows 2.8v... but the backlight output is always at 8,20v. The fuse, the diode are good. The vin is at 5.20v. The grounds are good. All the voltages around the backlight IC are good: SCLK, SDA at 3.3v except the PWM which is between 0.9 and 1.5v. I have changed the backlight IC, LP8550, new and original three times with still the same result: no backlight and still, 8.5v on its line....
What can I do more or should I change the board?????
Thanks for your advices!!!
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