Chosen Solution
Hey y’all I’m new to max repair. I opened up the MacBook Air (2017) and found a corroded capacitor. Cleaned it up a little bit but I think that this capacitor may be the reason the backlight isn’t turning on and am looking for a little input if this could be the issue. Also wondering how I can find the right capacitor to replace it with. I’ll upload a picture below from before I cleaned off the corrosion. I’m referring to the capacitor to the right of the display port with green corrosion on the right side of it. Thank you
Michael Sampino The corroded capacitor is reference designator C7797. It is a 10uF 50V 10% capacitor in a 1210 case. It is part of your backlight driver circuitry. You could check it for short to ground. I’d replace it anyway since it does show corrosion on it. As for your backlight, just test it on the LCD connector. Place your multimeter in diode mode. Red probe on ground and black probe on either 3 or 4. Pin 1 starts closest to the particular capacitor. Let us know what you get. As for voltages , Black to ground red to pins 3 or 4 and meter in volt mode, you should get around 27V or higher on a good working system, Again , let us know what you get.
I’d check the two filters as well (grey square with two connections) on a iPad resistance is around 0.14 ohms so hopefully they’ll have about that. They are usually backlight filters on iPads so maybe worth a test as well.
