Hi. Troubleshooting a macbook A1534 that will not power on. Computer appears to have some liquid (thin line) around the perimeter of the logic board and suspecting it is from the topside keyboard / trackpad area. No wet tag color sensors were triggered. Will review to clean it with an ultrasonic cleaner.
So far, applied an external Apple type C power adapter which emits 14.5v (approx.) after USB negotiations.
The current draw on the unit itself is oscillating between 30 mA and 0.6A.
The CPU shield area is warm to the touch. Some of the tantalum caps are @ 52 C after a few minutes of on time using an IR thermometer gun. The rails related to these caps are operating fine @ 8.6 volts (C1031 & C1032).
PP1V1_S0SW_SSD = 0 volts
PPBUS_G3H @ 8.6 volts which matches the value on sheet 60 of 75 PDF.
PPVIN_G3H_P3V3G3H @ 14.5 volts (same as input supplied by external power adapter) - but should be 8.6 volts (according to sheet 60).
Confused as to the start / end of this PPVIN_G3H_P3V3G3H rail.
From which feed does PPVIN_G3H_P3V3G3H get the 8.6 volts?
If PPVIN_G3H_P3V3G3H = 14.5 rather than 8.6 volts, does this imply that U7100 (ISL95530HIZ) is damaged? From my understanding, U7100 is to use the PPVIN_G3H_P3V3G3H as a Vcc so is an input to this switcher?
Please confirm. U7100 is quite expensive and may just conclude this motherboard to be not worth repairing.
Welcome any suggestions on this repair.
reference - downloaded the schematics & boardview brd file from this forum:
macbook-pro-a1534-82000045a-j92-schematics
Thanks!
So far, applied an external Apple type C power adapter which emits 14.5v (approx.) after USB negotiations.
The current draw on the unit itself is oscillating between 30 mA and 0.6A.
The CPU shield area is warm to the touch. Some of the tantalum caps are @ 52 C after a few minutes of on time using an IR thermometer gun. The rails related to these caps are operating fine @ 8.6 volts (C1031 & C1032).
PP1V1_S0SW_SSD = 0 volts
PPBUS_G3H @ 8.6 volts which matches the value on sheet 60 of 75 PDF.
PPVIN_G3H_P3V3G3H @ 14.5 volts (same as input supplied by external power adapter) - but should be 8.6 volts (according to sheet 60).
Confused as to the start / end of this PPVIN_G3H_P3V3G3H rail.
From which feed does PPVIN_G3H_P3V3G3H get the 8.6 volts?
If PPVIN_G3H_P3V3G3H = 14.5 rather than 8.6 volts, does this imply that U7100 (ISL95530HIZ) is damaged? From my understanding, U7100 is to use the PPVIN_G3H_P3V3G3H as a Vcc so is an input to this switcher?
Please confirm. U7100 is quite expensive and may just conclude this motherboard to be not worth repairing.
Welcome any suggestions on this repair.
reference - downloaded the schematics & boardview brd file from this forum:
macbook-pro-a1534-82000045a-j92-schematics
Thanks!
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