Can't get my 820-01700 to boot. ammeter says 5v and 0.05 amps. Board is a few years old, has no signs of corrosion at all.
I went through the power rails and measured them:
PPBUS_G3H - 12.3v
PPBUS_HS_CPU - 12.3v
PPBUS_HS_GPU - 12.3v
PPBUS_HS_OTH5V - 12.3v
PPBUS_HS_3V3G3H_T - 12.3v
PP3V3_UPC_XA_LDO - 3.38v
PP3V3_G3H_T - 3.37v
PP3V3_G3H_RTC_X - 3.38v
P3V3MAIN_PGOOD - 3.3v
PP1V8_SLPS2R - 1.86v
PP0V8_SLPS2R - 0.797v
PP1V1_SLPS2R - 1.1v
PMU_ONOFF_L - 3.37v
PMU_RSLOC_RST_L - 3.38v
PP1V2_AWAKE - 1.19v
PM_SLP_S4_L - 0v - 98k resistance to ground
PP5V_S5_LDO - 0.0v - 3.8k resistance to ground
PP5V_G3S - 0.0v - 260 ohm resistance to ground
P5VG3S_PGOOD - 0v - 69k resistance to ground
PP1V8_G3S - 0.0v - 211 ohm resistance to ground
Behavior and measurements are the same for all 4 usb ports.
Any ideas on where I need to look? The apple store wants $800 to replace the board. I'm trying to learn so I can do it cheaper.
I went through the power rails and measured them:
PPBUS_G3H - 12.3v
PPBUS_HS_CPU - 12.3v
PPBUS_HS_GPU - 12.3v
PPBUS_HS_OTH5V - 12.3v
PPBUS_HS_3V3G3H_T - 12.3v
PP3V3_UPC_XA_LDO - 3.38v
PP3V3_G3H_T - 3.37v
PP3V3_G3H_RTC_X - 3.38v
P3V3MAIN_PGOOD - 3.3v
PP1V8_SLPS2R - 1.86v
PP0V8_SLPS2R - 0.797v
PP1V1_SLPS2R - 1.1v
PMU_ONOFF_L - 3.37v
PMU_RSLOC_RST_L - 3.38v
PP1V2_AWAKE - 1.19v
PM_SLP_S4_L - 0v - 98k resistance to ground
PP5V_S5_LDO - 0.0v - 3.8k resistance to ground
PP5V_G3S - 0.0v - 260 ohm resistance to ground
P5VG3S_PGOOD - 0v - 69k resistance to ground
PP1V8_G3S - 0.0v - 211 ohm resistance to ground
Behavior and measurements are the same for all 4 usb ports.
Any ideas on where I need to look? The apple store wants $800 to replace the board. I'm trying to learn so I can do it cheaper.
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