BCConnection
Member
Still learning the M1 M2 power up process but here is what I checked and found
New port
Known good Apple Original 61W charger
PPVBUS USBC1 5v
PPBUS_AON 12.14V
PP3V8AON_PH1/PH2/PH3 all 3.747V
Poked around PMU found PP5v_BSTLQ_VOUT_MPMU shorted to ground
Bad cap
Line came up to 2.7V but still no 20V on charger. Line should be 5V
Looked at Schematic and saw the 5V is an output of a Buck power system created by the PMU.
Knowing how iPhone 6 series backlight circuits work and how their output caps failed causing the buck coil to internally fail.
Replaced L8300 with known good from an iPhone with the same 0.47UH rating.
Line came up to 5v and now get 20V on USB and Mac boots.
New port
Known good Apple Original 61W charger
PPVBUS USBC1 5v
PPBUS_AON 12.14V
PP3V8AON_PH1/PH2/PH3 all 3.747V
Poked around PMU found PP5v_BSTLQ_VOUT_MPMU shorted to ground
Bad cap
Line came up to 2.7V but still no 20V on charger. Line should be 5V
Looked at Schematic and saw the 5V is an output of a Buck power system created by the PMU.
Knowing how iPhone 6 series backlight circuits work and how their output caps failed causing the buck coil to internally fail.
Replaced L8300 with known good from an iPhone with the same 0.47UH rating.
Line came up to 5v and now get 20V on USB and Mac boots.
