Hello, I have a 820-02020 with history of water damage. Motherboard was not affected in anyway, backlight film needs replacing but customer did not want to pay.
2 months down the road, macbook is back with not turning on fault. upon inspection, L7800 is burned and U7700 is shorted. Replaced L7800 and U7700, now when the board feels like so it will boot, but will auto shutdown randomly. If it does not want to boot, its stuck 5v 0A. It also sometimes cycle 5v-20v but does not reach far enough into boot progression to get an apple logo.
Measurement when its stuck 5v 0A
ppbus_aon = 12.2 (pulsing)
pp3v3_s3 = 3.3 (pulsing) Measure EN from U8100 also pulsing.
pp3v8_aon = 3.78v steady.
2 months down the road, macbook is back with not turning on fault. upon inspection, L7800 is burned and U7700 is shorted. Replaced L7800 and U7700, now when the board feels like so it will boot, but will auto shutdown randomly. If it does not want to boot, its stuck 5v 0A. It also sometimes cycle 5v-20v but does not reach far enough into boot progression to get an apple logo.
Measurement when its stuck 5v 0A
ppbus_aon = 12.2 (pulsing)
pp3v3_s3 = 3.3 (pulsing) Measure EN from U8100 also pulsing.
pp3v8_aon = 3.78v steady.
