Model: MacBook 12” (Early 2015, A1534)
The customer found that their MacBook couldn’t power on. 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.
They visited different repair centers, but some only provided quotations for logic board replacement, with data loss.
Since the customer has no recent backup, they chose to have the logic board repaired at iCertified to try to keep the data.
Inspection begins:
After inspection by our technicians, it was found that the USB-C charging voltage was only 5V which should boosted to 20V on one side. The other side of the USB-C charging has no response. This indicates a potential issue with the USB-C charging components on the logic board.
After providing a repair quote to the customer, they decided to proceed with the repair.
Repair begins:
Since there is no response on one side of the USB-C charging, the USB-C configuration channel signal were directly inspected.
Measurements revealed abnormal readings in the diode mode measurement of the USB-C configuration channel signal E85_CC2, indicating possible damage to the USB-C communication IC SLG4AP645AV.
Replacing the USB-C communication IC resolved the detecting issue on both sides of the USB-C charging, but the charging voltage is still only 5V which should boosted to 20V.
Measurements revealed abnormalities in the power rail PPDCIN_G3H, with a voltage reading of 5V, and other power rails including PP3V3_G3H and PPBUS_G3H, with a voltage reading of 0V.
Measurements revealed abnormalities in the power rail of USB-C communication IC SLG4AP645AV, PP3V3R3V0_AON was shorted to ground.
Using an infrared thermal imaging camera, it was observed that the ARM microprocessor LPC11U37FET48-CP3316 was experiencing abnormal heating.
After removing the ARM microprocessor, the power rail returned to normal and no longer shorted to ground.
After soldering the ARM microprocessor, the MacBook was able to power on.
To reduce the chances of encountering the same issue, our technicians replaced the USB-C port as well, there are signs of burn marks on the pin VBUS and CC2 on the old USB-C port, it is believed that this is the reason of damaging the USB-C communication IC SLG4AP645AV and ARM microprocessor LPC11U37FET48-CP3316.
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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