Model: MacBook Air 13” (Early 2014, A1466)
The customer found that their MacBook Air couldn’t power on, but the charging was functioning properly. They visited the Genius Bar and were informed that the logic board needed to be replaced. However, due to the model being considered vintage and parts for replacement being unavailable, the repair was not possible.
The customer chose to have the logic board repaired at iCertified so they could continue to use their MacBook Air.
Inspection begins:
After inspection by our technicians, it was found that although the charging seemed to be normal, the current of the MagSafe power supply was only 0.019A after removing the battery, indicating a logic board failure.
After providing a repair quote to the customer, they decided to proceed with the repair.
Repair begins:
Since the charging seemed to be normal, it was estimated that the issue occurred after the generation of the SMC power rail PP3V42_G3H. The power rails following PP3V42_G3H in the power-on sequence were directly inspected.
Measurements revealed abnormalities in the power rail PP3V3_S5, with a voltage reading of 0V.
The enable signals SMC_PM_G2_EN and P3V3S5_EN_R for this power rail were normal, indicating that the issue may lie with the TPS51980A or CSD58873Q3D.
Measurements revealed abnormal readings in the diode mode measurement of P3V3_S5_DRVH and P3V3_S5_LL, suggesting that the CSD58873Q3D was damaged.
Replacing the CSD58873Q3D resolved the no power-on issue.
After cleaning and installing the logic board, all functions were tested and found to be normal, without data loss.
Repair completed.
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