820-00165 issues - waht can i do
Hello community, I have a MacBook Air 820-00165 with an i5 and 8GB Ram. The logic board doesn't want to start. I've taken some measurements but I can't really get any further.
And please excuse me if something is spelled wrong, I have to use a translator.
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PPBUS_G3H = 8.6 V (stable)
PP3V42_G3H = 3.44 V (stable)
First Always/SMC signals
SMC_RESET_L = 3.4 V (stable → SMC running)
SMC_PM_G2_EN = pulses between 0 V ↔ 3.3 V
PM_PWRBTN_L = pulses between 0 V ↔ 3.3 V
PM_SLP_S5_L = pulses between 0 V ↔ 0.2 V
S5/S4 supplies
PP3V3_S5 (L7520) = pulses 0 ↔ 3.3 V (not stable, “hiccup”)
PP5V_S4RS3 (L7560) = 0 V (does not come up because 3V3-S5 is missing)
Regulator U7501 / Power Good
PGOOD1 (3V3) = 0V
PGOOD2 (5V) = pulses between 0 ↔ 3.3 V
P3V3S5_EN_R = pulses between 0 ↔ 3.3 V
P5VS4RS3_EN_R = 0V
S5_PWRGD (U8130) = pulses between 0 ↔ 3.3 V
U7501 internal pins
VREG5 = 5 V, drops briefly every ~2 s
VREG3 = constant 3 V
VREF2 = 2 V, drops synchronously with VREG5
SW1 (3V3 branch) = 0 V (no switching visible)
Resistance measurements (without current)
A1 (PP3V3_S5 → GND) = 3.1 kΩ (no short circuit)
R7560 (5V divider) = correct 23.2 kΩ
R7522 = 3 Ω (perhaps correct according to the plan, but needs to be checked in context → not the feedback divider)
R7537 = unequipped (no-stuff, normal)
and.. yes I actually use an AI to help BUT! I can't get any further because I don't know what else I should or can do.
It feels like I measure the same signal 3 or 4 times and suddenly it's component XYZ... So you can't really call it a help.
And please excuse me if something is spelled wrong, I have to use a translator.
-------
PPBUS_G3H = 8.6 V (stable)
PP3V42_G3H = 3.44 V (stable)
First Always/SMC signals
SMC_RESET_L = 3.4 V (stable → SMC running)
SMC_PM_G2_EN = pulses between 0 V ↔ 3.3 V
PM_PWRBTN_L = pulses between 0 V ↔ 3.3 V
PM_SLP_S5_L = pulses between 0 V ↔ 0.2 V
S5/S4 supplies
PP3V3_S5 (L7520) = pulses 0 ↔ 3.3 V (not stable, “hiccup”)
PP5V_S4RS3 (L7560) = 0 V (does not come up because 3V3-S5 is missing)
Regulator U7501 / Power Good
PGOOD1 (3V3) = 0V
PGOOD2 (5V) = pulses between 0 ↔ 3.3 V
P3V3S5_EN_R = pulses between 0 ↔ 3.3 V
P5VS4RS3_EN_R = 0V
S5_PWRGD (U8130) = pulses between 0 ↔ 3.3 V
U7501 internal pins
VREG5 = 5 V, drops briefly every ~2 s
VREG3 = constant 3 V
VREF2 = 2 V, drops synchronously with VREG5
SW1 (3V3 branch) = 0 V (no switching visible)
Resistance measurements (without current)
A1 (PP3V3_S5 → GND) = 3.1 kΩ (no short circuit)
R7560 (5V divider) = correct 23.2 kΩ
R7522 = 3 Ω (perhaps correct according to the plan, but needs to be checked in context → not the feedback divider)
R7537 = unequipped (no-stuff, normal)
and.. yes I actually use an AI to help BUT! I can't get any further because I don't know what else I should or can do.
It feels like I measure the same signal 3 or 4 times and suddenly it's component XYZ... So you can't really call it a help.
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