MacBook Air A2179 clicking sound from CPU area repair

Problem description
If you hear clicking sound from CPU area, this most likely means that the CPU is shorted in one way or another. 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.

Symptoms

 * MacBook not turning on
 * Clicking sound from CPU area

Solution
The only way is to replace the CPU. This requires a BGA rework station and lots of experience. If you've never done this before then taking it to a professional or replacing the whole motherboard is the only solution.