Apple MacBook Air A2179

Problem Description	Symptoms	Solution	Source
No power.	- Clicking sound coming from CPU area.	If you hear a clicking sound from the CPU area, this most likely means that the CPU itself is shorted. Clicking sound likely originates from L7400, which powers many internal PCH functions. Clicking results from magnetic resonance within the coil, due to high load on the circuit from a shorted PCH/CPU. Only fix is to replace the CPU.	Source
No power.	- Pulls 5V 180-220mA at first then drops to 20mA - P5VG3S_EN missing - All rails below PP5V_G3S are present	Replace U7800	Source
No power.	- Pulls 5V 0A - All standby voltages are 0V - PP3V3_G3H 0.9V, PP3V3_G3H_RTC 3.3V	PMU_VDD_HI signal is not reaching U7800, likely due to R8050.
No power.	- P5VG3S_EN is missing.	Caused by a dead or corrupted T2 chip.