What I also did right now:
- disconnected board from power supply
- multimeter set in DC mode at 2v unit
- black probe on GND board
- red probe on P1V8SUS_SW (at L8020), while keeping the red probe, connected the power supply -> no change on the multimeter, 0V
- another test similar as above, but red probe this time on the positive feedback at P1V8SUS_FB_RC from R8025, connected the power supply -> no change on the multimeter, 0V
rilley
Member
Last Activity: 01-05-2025, 03:34 AM
Joined: 07-07-2024
Location: RO
-
Also measured right now the:
C8020 - resistance, 7kOhm.
R8025 - resistance, 99,9Ohm.Leave a comment:
-
Thank you Mon2 & Reformatt for your prompt response and for helping me out!
Did some measurements:
PP5V_PMICLDO = 5,13v (at C8025 and at the test pad) - OK
Feedback positive resistance has 10ohm (R8021) - OK
Feedback negative resistance has 99ohm (R8020) - OK
GND and L8020 resistance has 2kOhm (at P1V8SUS_SW bottom side of the inductor) - I think is OK
L8020 resistance as inductor on both sides (has continuity) - I think is OK
PP3V3_S5 near U7800 ( C8020 ) = 3,35V - I think is OK
PP3V3_PMICLDO ( at C7839 ) = 3,2V -...Leave a comment:
-
Could it be that this PP1V8_SUS is generated somewhere else and I need to dig elsewhere and not on the U7800 ?
( seems like the R8024 is not on the board, along with R8029, C8029 will definitely will not help to go further with PP1V8_S0, but from what I saw on the board, there are places that are missing components, but I think they are not there by Apple and nobody removed them [like old repair shop], see the red circle from the past photos that I made with the board, seems like there are small circles with flux ).
Also, without PP1V8_S0, and PPBUS_HS_CPU, then I won't...Leave a comment:
-
What I found so far:
Part 1:
====================================================
PM_SLP_SUS_L = 3,35v
R8024 is not on the board, along with R8029, C8029.
>> but it seems that there weren't anyway, I think nobody remove them, doesn't seems to be trace of flux or heat there (see attached photos).
So my understanding is, without that R8024 it can't convert the P1V8SUS_SW (AC) to P1V8SUS (DC) needed for PP1V8_S0.
PP1V8_S0 measured in resistance mode, and is not in short.
I don't have an oscilloscope, measured...Leave a comment:
-
Did two measurements, multimeter in resistance mode at 20k unit, black probe at GND, and red probe:
EDP_INT_AUX_N
4,68
EDP_INT_AUX_P
4,62
EDP_INT_AUX_N
4,64
EDP_INT_AUX_P
4,59
...Leave a comment:
-
At the moment I'm trying to boot it up without display and any other major peripherals.
And from my understanding, I'm stuck at missing: ALL_SYS_PWRGD and missing:
PP1V8_S0
PP1V8_SUS...Leave a comment:
-
I tried to debug why PP1V8_S0 = 0 Volts
See attached PDF with the analysis.
I think it has connections with PP1V8_SUS which comes 0v from U7800
And also it has missing components (attached a photo with the board), not sure if it helps as PP1V8_SUS_REG_R is 0volts that comes from U7800
From my understanding if I don't have PP1V8_S0, then [B]ALL_SYS_PWRGD[/B] is low (0volts), then the whole system can't continue booting, right?I tried to debug why PP1V8_S0 = 0 Volts
See attached PDF with the analysis.
I think it has connections...Leave a comment:
-
Hello Piernov, thank you for the input.
The only damage that I saw on the board with a magnifier, was on the pin PP5V_S0_ALSCAM_F on the display side, and on the board, and resistor L4004 burned.
And I've checked, I have [B]PP5V_S0 = 5,1v.[/B]
Should I remove the heat sink from the CPU to see if everything is intact?Hello Piernov, thank you for the input.
The only damage that I saw on the board with a magnifier, was on the pin PP5V_S0_ALSCAM_F on the display side, and on the board, and resistor L4004 burned.
And I've checked, I...Leave a comment:
-
[B]Did some measurements with the board connected to power charger on USB-C.[/B]
[B]PPBUS_G3H[/B]
[B]= 13V[/B]
[B]PP3V3_G3H[/B]
[B]= 3,4V[/B]
[B]PP3V3_S5[/B]
[B]= 3,3V[/B]
[B]PP5V_S5[/B]
= 5,13V
[B]PP3V3_S0[/B]
= 3,3V
[B]PP5V_S0[/B]
= 5,1V
[B]PP1V8_S0[/B]
= 0V
CPUCORE_SW1
CPUCORE_SW2
= 0V
PPVOUT_S0_LCDBKLT
= 0V
PP3V3_SUS
= 3,2V
Leave a comment:
-
The PPBUS_G3H at C6484 it is 13V stable.
...Leave a comment:
-
I've re-checked the [B]ALL_SYS_PWRGD[/B], black probe to GND, and measure unit to DC red to [B]ALL_SYS_PWRGD[/B], still 0V, when I touched the red probe, I've noticed small changes on the measure unit, but still 0V. ( measure unit set to 20v threshold )I've re-checked the [B]ALL_SYS_PWRGD[/B], black probe to GND, and measure unit to DC red to [B]ALL_SYS_PWRGD[/B], still 0V, when I touched the red probe, I've noticed small changes on the measure unit, but still 0V. ( measure unit set to 20v threshold )I've re-checked the [B]ALL_SYS_PWRGD[/B], black probe to GND, and measure unit to DC red toLeave a comment:
-
At C7029 I have 20.4VLeave a comment:
-
That charger 61W came with the mac, and it worked.
Anyway, recently I've switched to 96W as I have one that works.Leave a comment:
-
Measured the PP3V3_S0 at R5860, and I have 3.35v
...Leave a comment:
-
I've checked at the [B]ALL_SYS_PWRGD test pad, [/B]while board connected to the power adapter only (no other cables connected to it), I have 0v on that.I've checked at the [B]ALL_SYS_PWRGD test pad, [/B]while board connected to the power adapter only (no other cables connected to it), I have 0v on that.I've checked at the [B]ALL_SYS_PWRGD test pad, [/B]while board connected to the power adapter only (no other cables connected to it), I have 0v on that....
Leave a comment:
-
Thanks for answering about the CPU, this is a relief as this board might have chance to work.
About the bidirectional USB C meter, will try to buy one soon.
I tried also connecting the board with the keyboard flex, and trackpad flex, did the SMC_ONOFF_L and nothing happened, no fan..
What I saw, the trackpad seems to work, when I touch it, it has that "force touch" sound.
What I also noticed if I had the battery + battery status cable connected, it started to charge it, as I noticed the power adapter transformer was warm, and after...Leave a comment:
-
I'm attaching here some pictures that I took with the board, and will respond afterwards with more details. (sorry if it might be bad quality, took them with my iPhone and the lighting right now is dark here, will do more in the next days if needed)...
Leave a comment:
-
Thanks for helping me out!
With board out of any connectivity and cables.
First measurement I did:
- Multimeter in resistance mode, at 200
- Black probe at GND of the motherboard
- Red probe of multimeter at CPUCORE_SW1 ( from L7210 )
- Red probe of multimeter at CPUCORE_SW2 ( from L7220 )
>>>> On both core test had 6.1 ohm
Second measurement I did:[LIST][*]Multimeter in resistance mode, at 20k[*]Black probe at PPBUS_G3H ( from C6483 where I had 13V in the past )[*]Red probe at PPVCC_CPU_PH1 and then...Leave a comment:
-
Thank you for clarification.
Tried to short to ground the SMC_ONOFF_L for a few seconds while the power cable was connected, board outside with no other peripherals connected.
Also tried to start the board with SMC_ONOFF_L bridged to GND for 10 seconds and then connected the power, and released the SMC_ONOFF_L, but nothing happened, CPU heat sink is cold.
I only have a multimeter, I don't have oscilloscope, and I don't have that USB-C multi meter that I can measure the 20V / and amper from cable. (will buy one in the future)
I can't measure...Leave a comment:
No activity results to display
Leave a comment: