Macbook Air 820-3437 Dead: no s5_pwrgd: MISTERY

[phantomEVO]

PPBUS at 8.6V
No Fan Spin
I get Magsafe light (green than orange with or without battery)


motherboard water spill (cleaned from another techician)

3V3_S5 present
3V3_Sus not present
P3V3SUS_EN 0v
PM_SLP_SUS_L 0v (no short)


PM_PWRBTN_L 0,3v
SPIROM_USE_MLB 0v
S5_PWRGD 0v

PCH_DSWVRMEN - 3,1 3v
PM_BATLOW_L - 3.4v
SMC_ADAPTER_EN - 0v
RTC_RESET_L 3,3
PCH_SRTCRST_L 3,3
PCH_INTRUDER_L 2,5 and PCH_INTVRMEN 3v

SMC_S5_PWRGD_VIN present
s5_pwrgd 0v

0v on one side of r8141, 3,3 in the other side of the resistence

r8141 and u7501 changed ,,,,still 0v

[mon2]

What is the voltage to ground of SMC_BC_ACOK (u7100)?

Required to fix SMC_ADAPTER_EN logic level.

[phantomEVO]

SMC_BC_ACOK is 3,3v (0,470in diode mode)

SMC_ADAPTER_EN is 0v

[mon2]

What is the voltage to ground of PP3V42_G3H @ L7095. This should be a stable 3v42.

Also, from a post by piernov (see below for the thread):

As expected on 820-3437 without battery.

Do you have a known good battery attached?

[phantomEVO]

0,320, 3V42 stable i conFIrm

[phantomEVO]

with or withou battery, same result

[phantomEVO]

is it normal that S5_PWRGD is 0,3v ?

i have 3,4 on the other side of r8141

even changing resistence and u7501, same result

[mon2]

is it normal that S5_PWRGD is 0,3v ?

No it is not. Power good signals are 99% of the time, open-drain type. If the power rail is deemed to be OK, then this output signal will be hi-z / open-circuit / floating. For this reason, the external pull-up resistor MUST be present to park the floating line to a 'soft high'. Only if the power rail is not within specs, then the same regulator will pull this line to a logic low.

Remove all power -> measure the resistance to ground of PP3V3_S5_REG_R @ L7560.

What is the voltage to ground of PP3V3_S5_REG_R ?

[phantomEVO]

3,3K; 0,355

[mon2]

So it is not shorted. What is the voltage of this rail when on? Do also check the voltage of the enable signal.

This regulator may be defective.

[phantomEVO]

2,8V when power supply connected

which is the enable signal?

[mon2]

2v8 is too low for this 3v3 power rail. You should have a stable 3v3 at the output. The enable signal is fine since you have a voltage. Replace this regulator. The 2v8 is too low and the power good signal is being pulled low to announce this status of this power rail.

Also see attached. These are the feedback resistors that must be present and accurate to dial up the 3v3 output voltage. Do check these without power to the board. Then proceed to replace the regulator. Keep posting your updates.

[phantomEVO]

i already replace u7501 from anotherboard...

i have told you some post before

[mon2]

Double check your work of this replacement part. The resistors are ok as requested in post # 12 ? Monitoring 20+ posts per day here so do bear that in mind.

[phantomEVO]

Update: this is the voltage PP3V3_S5_REG_R if i put probes right before connecting power supply



https://www.dropbox.com/scl/fi/yi41k...pcctutaa4&dl=0

[phantomEVO]

R7563 15 ohm
R7560 9,5k
R7561 7k

same readings of another motherboard

[phantomEVO]

i'm going crazy..i think i will commit suicide....pleas mon2...forgive me for all this chaos....


i have soldered a BRAND NEW U7501...now i miss some voltages...help


3V3_S5 not present
3V3_Sus not present
P3V3SUS_EN 0v
PM_SLP_SUS_L 0v (no short)


PM_PWRBTN_L 0 v
SPIROM_USE_MLB 0v
S5_PWRGD 0v

PCH_DSWVRMEN - 3,28
PM_BATLOW_L - 0v
SMC_ADAPTER_EN - 0v
RTC_RESET_L 3,4
PCH_SRTCRST_L 3,3
PCH_INTRUDER_L 2,5 and PCH_INTVRMEN 3,2v

[mon2]

1) Post pics of this reworked area.

2) Suspecting that you will need to properly reflow this component. High enough air pressure and heat to melt the solder so that the part swims into place. Review some of the YT videos on the topic. Hover over the part in tight circles to apply heat to evenly melt the solder pads into place. They will align like soldiers as Louis states in his many videos. Use tweezers at corners if required to nudge the part but only when the solder is melted. Be patient and do not lose any surrounding parts. As long as the part being used for the replacement is identical and known good, these voltage rails should return.

PM_PWRBTN_L 0 v

The power button is stuck low and needs to return to a logic high to operate.

12. PM_PWRBTN_L (PWRBTN#) power button on/off. If the logic board is connected to the battery only, you need to press the power button on the keyboard to send a high-low-high pulse to the CPU/PCH (via SMC). If you connect the logic board to the charger only without connecting the battery, once SMC receives the SMC_BC_ACOK from charging circuit power management IC u7100, SMC will output SMC_ADAPTER_EN (ACPRESENT). In this case, the signal SMC_ADAPTER_EN will act as the same as PM_PWRBTN_L. In other words, the PM_PWRBTN_L is not always a “must" in some situation. It is why we call it “+1" condition. When the 11 prerequisites are met, once you press the power button (PM_PWRBTN_L) or connect a charger to the logic board (SMC_ADAPTER_EN), CPU/PCH will shoot out PM_SLP_S5_L, PM_SLP_S4_L and PM_SLP_S3_L to enable S4, S3 and S0 state power rails.

reference:

PM SLP S4 L Timing Troubleshooting - LogiWiki

[phantomEVO]

u7501 is perfectly soldered! i'm going crazy believe me...

however i've check all voltages with power supply only...

i'm very tired...could you give me what to do now?

thank you mon, you are a friend!

[mon2]

1) You must use the official and original power adapter from Apple.

2) Review this flow chart:

G3 to S3 State for Ivy Bridge Haswell and Broadwell - LogiWiki