Power Button not Woking even after keyboard and flex cable replacement

Hello,

I have a MacBook Air 2013 11’’ motherboard number 820-3435.

The power button is not working (its the only key in the keyboard that is not working) even after keyboard, touchpad and touchpad/keyboard flex cable replacements, which leaves me with a bad motherboard.

The question is, where to start? The schematics says pin 20 in the keyboard connector is has the line SMC_ONOFF_L, that then goes to resistor R5116. The thing is, i dont see a resistor there, only the turn on pads, and measuring continuity from pin 20 to the pads gives me nothing.

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What steps did you take to confirm the power button isn't working? Is the machine able to power on if you disconnect the battery, reconnect the battery, then connect a power adapter? Do you see any change in the charger LED when you perform an SMC reset?

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Yes, the machine powers on when i disconnect the battery and connect the power adapter, and when i contact the power on pads on the motherboard

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