Step-by-step troubleshooting process on MacBook Pro A1398 No Power Repairs скачать в хорошем качестве

Step-by-step troubleshooting process on MacBook Pro A1398 No Power Repairs

We received a MacBook Pro A1398 with a no-power fault. A step-by-step diagnostic process was carried out to identify and resolve the issue. We first confirmed charger communication by checking for the LED indicator on the MagSafe 2 adapter. The presence of the LED indicated that initial power negotiation was successful and that primary rails such as PPDCIN and PP3V42_G3H were present. Next, we measured voltage at PPBUS_G3H and other relevant power rails to trace the fault path. During testing, we narrowed the issue down to a short to ground on the PP3V3_S0 rail. Power was then disconnected from the board and voltage was injected into the affected line to locate the shorted component, as the faulty part would heat up under injection. This process led us to identify U8030 as the defective component. After replacing U8030, the short was cleared and the power issue was resolved. For any questions regarding this repair or other related services, please feel free to leave a comment.