gl33ntwine
New member
Hello! We had a MacBook A2159 come in the other day with the symptom "died in the middle of normal usage", no liquid damage according to the client.
Found shorted CD3217, replaced it, after confirming the short is gone tried plugging it in. Got 5V 0.4A on both ports but on battery the laptop did turn on and work (still taking in only 5V/.4A from the charger). Replaced the second CD3217 and their TBT ROM just in case, no change. Was going through the official power sequence schematic measuring everything. All voltages were pulling up fine up until PMU_PVDDMAIN_EN. Noticed also U7800/PMU getting slightly warm. Double-checked all inputs to U7800 and R7900 - no problems there. Swapped U7800 with a known good just in case. No change. Just out of interest, swapped the battery for a new one, now it's 20V/0.16A with battery and charger connected and 5V/0.4A with only charger connected (battery disconnected). No idea where to dig next.
The device does enter DFU (indicated by SOC_DFU_STATUS) but the host Mac does not recognize it - there are some kernel logs of USB device init but that never finishes completely. Tested also USB accessories in a booted system, also weird - when I plug in a known working usb flash drive, the indicator on it lights up but the system does not react. But as soon as I plug it out, the OS shows a notification "Plug the *usb device name* in!" so some sort of communication between them does happen albeit not fully successfully.
After multiple close inspections of the board, found traces of previous repairs - apparently there was small liquid spillage around R5400 a long while ago. Just in case, lifted all the elements here and found some corrosion - cleaned up and replaced everything. Also found a chipped D3370, replaced that. Also chipped D3329 and missing DZ3304. DZ3301, DZ3302, D3329, D3304 in general looked weird, temporarily removed all four for good measure. No change.
No idea where to dig next. Is this T2 death?
Found shorted CD3217, replaced it, after confirming the short is gone tried plugging it in. Got 5V 0.4A on both ports but on battery the laptop did turn on and work (still taking in only 5V/.4A from the charger). Replaced the second CD3217 and their TBT ROM just in case, no change. Was going through the official power sequence schematic measuring everything. All voltages were pulling up fine up until PMU_PVDDMAIN_EN. Noticed also U7800/PMU getting slightly warm. Double-checked all inputs to U7800 and R7900 - no problems there. Swapped U7800 with a known good just in case. No change. Just out of interest, swapped the battery for a new one, now it's 20V/0.16A with battery and charger connected and 5V/0.4A with only charger connected (battery disconnected). No idea where to dig next.
The device does enter DFU (indicated by SOC_DFU_STATUS) but the host Mac does not recognize it - there are some kernel logs of USB device init but that never finishes completely. Tested also USB accessories in a booted system, also weird - when I plug in a known working usb flash drive, the indicator on it lights up but the system does not react. But as soon as I plug it out, the OS shows a notification "Plug the *usb device name* in!" so some sort of communication between them does happen albeit not fully successfully.
After multiple close inspections of the board, found traces of previous repairs - apparently there was small liquid spillage around R5400 a long while ago. Just in case, lifted all the elements here and found some corrosion - cleaned up and replaced everything. Also found a chipped D3370, replaced that. Also chipped D3329 and missing DZ3304. DZ3301, DZ3302, D3329, D3304 in general looked weird, temporarily removed all four for good measure. No change.
No idea where to dig next. Is this T2 death?
