MacBook Pro A1502 No green light on charger repair

Problem description

 * 1) incomplete

Symptoms

 * Green light on charger not turning on

Solution
This problem has multiple causes:


 * ADAPTER_SENSE not 3 V due to bad DC in board. 16–20 V on ADAPTER_SENSE means charger voltage is leaking into ADAPTER_SENSE, below 2 V means it is missing usually due to a bad DC In board.
 * PP3V42_G3H missing
 * SMC not working(if SMC is off, you will have 12.23 V on PPBUS_G3H instead of 12.56 V) because it is dead, not turning on(SMC_RESET_L low).
 * Corrosion of the SMC's solder connections
 * Keyboard bad, shorting PP3V42_G3H to ground or power button stuck on.
 * Bad U7000
 * Bad U7001
 * Bad U7100 — indicators: PPBUS_G3H Below 4 V, board taking 40 mA, U7100 getting warm (check via thermal camera)