A1707 no backlight


New member
Embarking on a journey of electronic restoration, I received a MacBook 15" model A1707, board number 820-01041-A, which had faced a formidable challenge: significant liquid damage due to an unfortunate milk spillage on its motherboard. Determined to breathe new life into this machine, I began the meticulous process of repair.

The initial obstacle was a compromised CD3215 chip, essential for the MacBook's power management. After replacing this chip, I was able to restore the critical 20V power supply, a small yet significant victory in the repair saga. However, this triumph was quickly overshadowed by the discovery of a short circuit at fuse F7000. Tracing the root cause, I identified the U7410 chip as the culprit. Replacing it brought a sense of achievement as the MacBook finally powered up, its startup chime and the display of the Apple logo signaling a successful step forward.

Despite this progress, a persistent issue loomed: the MacBook's screen lacked backlight, a vital element for its functionality. In pursuit of a solution, I replaced the ribbon cable connecting the screen to the motherboard, a typical fix for such issues. Yet, this attempt did not yield the desired result. Furthering my efforts, I tested the machine with an alternative screen, only to face the same challenge.

My attention then turned to the F8400 fuse, which I found to be well-powered and free from short circuits around the U8400 chip. This discovery, while valuable, left the backlight issue unresolved.

Any idea ?