PPBUS 13v, job done.
All assembled and working now. Thanks for your help!
BillyJ
Member
Last Activity: 05-18-2022, 08:00 AM
Joined: 10-31-2021
Location: London
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Re: 2017 Apple MacBook Pro 13 inch touchbar A1706 - Not turning on - PPBUS Short?
PPBUS 13v, job done.
All assembled and working now. Thanks for your help!
Last edited by BillyJ; 01-04-2022, 05:22 PM. -
Re: 2017 Apple MacBook Pro 13 inch touchbar A1706 - Not turning on - PPBUS Short?
good point... both those sets of inductors are for the 3 phase DCDC converters supplying I think 0.5 to 1.5V.
I did apply 0.5V to them after that comment and took a look with a thermal camera. It didn't slam into the 0.2A current limit and there were no clear hotspots so I'm pretty confident I agree with you.
So this F7000 removal, what am I aiming to learn? after changing that cap out, the resistance to ground from PPBUS_G3H (with F7000 fitted) settles at approx 39k. Very...Leave a comment:
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Re: 2017 Apple MacBook Pro 13 inch touchbar A1706 - Not turning on - PPBUS Short?
Not got access to the BRD file right now but I gave the wrong designator. It was not C3505 but instead one of the 33uF B3 case caps (C3502 to 3504).
I removed that and the short had gone so replaced it with 3 parallel 10uF ceramic caps as that was all I had.
before trying to power up and check the PPBUS_G3H rail, I'm unsure about those inductor to ground measurements...
They're still <8 ohms on the group of inductors mentioned above which seems... sub-opti...Leave a comment:
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Re: 2017 Apple MacBook Pro 13 inch touchbar A1706 - Not turning on - PPBUS Short?
haha my thoughts exactly! It could definitely pull PPBUS_G3H down so hopefully that's the only fault.
Couldn't see it yesterday as the motherboard was still in the machine due to a screw which was rounded out. Ended up doing lots of masking and then Dremel-ing a slot into the head to remove. That wasn't fun - would not recommend
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Re: 2017 Apple MacBook Pro 13 inch touchbar A1706 - Not turning on - PPBUS Short?
Thanks for your reply!
I haven't had a chance to remove the fuse but found a 1.12 ohm short across a very burnt C3505.
I will pull it off and check the fault goes tomorrow.
To answer your q about the board number:
820-00923 ALeave a comment:
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2017 Apple MacBook Pro 13 inch touchbar A1706 - Not turning on - PPBUS Short?
Hi all,
Is there a boot-up sequence for the A1706 (Kaby lake) to see where the computer is getting stuck? Equiv to the below for older MBP's?
[url]https://logi.wiki/index.php/G3_to_S3_State_for_Ivy_Bridge_Haswell_and_Broadwell[/url]
currently I measure:
PP20V_USBC_XB_VBUS = 20
PPDCIN_G3H_CHGR = 20.4
PPDCIN_G3H = 20.4
SMC_RST_L = 3.4
PM_EN_P3V3_G3H = 5.2
PP3V3_G3H = 3.4
PPBUS_G3H = 0V (2.1 Ohm to GND - ISL9239 failure?)
S5:
PP3V3_S5 = 0
PP5V_S5 = 0.346
PPBUS_HS_OTH3V3 = 0.0186
PPBUS_HS_OTH5V... -
Re: Troubleshooting dead Apple MacBook Pro A1398 (820-00426-A)
Was preparing to start exactly that but it was working this AM again.
Left the cover off the base for the day, gave it some hot air gun action in case there was some condensation under an IC or something and it's working fine now.
Expecting it to fail again at some point haha and hopefully getting a new 14” MBP in Jan.
Thanks for your help with this issue. Glad I managed to narrow it down and fix.Leave a comment:
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Re: Troubleshooting dead Apple MacBook Pro A1398 (820-00426-A)
Cleaned the PCB and dried in an oven at 60degC for a few hours and it worked perfectly.
Problem solved.
Used it for about an hour and then went to unlock from sleep where it died and I got 3 beep followed by 5 second pause on repeat. A quick Google shows this is a System integrity check failure - typically ram.
Any thoughts?
Feels like back to square one.Leave a comment:
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Re: Troubleshooting dead Apple MacBook Pro A1398 (820-00426-A)
PP5V_S0 = 5.049
PP3V3_S0 = 3.326
PP1V5_S0 = 1.515
For info I've attached the rising batlow voltage. You can still see the dip which I assume is where the SMC checks or something but it “passes” and voltage rises....Leave a comment:
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Re: Troubleshooting dead Apple MacBook Pro A1398 (820-00426-A)
Ok wtf.
Was playing around measuring Q3000 as it's the only other device apart from the SMC that interacts with PM_BATLOW_L and started seeing a voltage on that line which surprised me.
Long story short, the batlow signal was having me over and I now get S0 voltage. No idea why.
Not sure what to do now…
Ultrasonic clean in deionised water and IPA then rinse in IPA, oven dry and reassemble?
Genuinely unsure how to take this forward.
Will measure...Leave a comment:
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Re: Troubleshooting dead Apple MacBook Pro A1398 (820-00426-A)
SMC 32khz clock is indeed 32khz
Goes high on power up, approx 22mS delay then starts clocking at 32khz
Pic attached. Seems like normal behaviour.
Bat low signal starts to climb for approx 300uS and is quickly grounded. Not sure what signals are used in that logic so unsure what else to put on the other channels for timing etc....Leave a comment:
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Re: Troubleshooting dead Apple MacBook Pro A1398 (820-00426-A)
I'll hold off on the ultrasonic bath for now.
SMC_RESET_L = 3.3V
PP1V2_S5_SMC_VDDC = 1.2V
PP3V3_S5_SMC_VDDA = 3.41V
PP3V3_S5_AVREF_SMC = 3.3V
SMC_WAKE_L = 3.125V
GND_SMC_AVSS = <0.5 Ohm to GND
SMC Bypass did not spin up fans.
I connected both fans and the keyboard. Held the on button (which I have confirmed works) and connected magsafe. Did this both with and without the battery connected and nothing from the fans even after 15s of holding the...Leave a comment:
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Re: Troubleshooting dead Apple MacBook Pro A1398 (820-00426-A)
really hoping some bug shit induced corrosion isn't my issue here haha but fair point well made about difficult/impossible to see corrosion.
I've had all the other boards and looms removed, only the logic board and MagSafe adaptor attached.
G3H:
PPBUS_G3H = 12.685V
PPDCIN_G3H = 16.721V
PP3V42_G3H = 3.4132V
S5:
PP5V_S5 = 5.0194V
PP3V3_S5 = 3.3281V
All the 11+1 requirements present EXCEPT PM_BATLOW_L are present.
(Haven't...Leave a comment:
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Re: Troubleshooting dead Apple MacBook Pro A1398 (820-00426-A)
Also found somewhere online explaining the 11+1 requirements for PM_SLP_S4_L = HI.
I measured all those (below) and odd that PM_BATLOW_L = 0V as there is no battery present...
1. PPVRTC_G3H = 3.38v
2. RTC_RESET_L = 3.3218
3. PCH_SRTCRST_L = 3.3215
4. PCH_INTVRMEN_L = 3.23
5. PCH_DSWVRMEN_L = 3.23
6. SYSCLK_CLK32K_RTCX1 = Pending measurement
7. PP3V3_S5 = 3.327
8. PM_DSW_PWRGD = 3.41
9. PP3V3_SUS = 3.327
10. PM_BATLOW_L = 0...Leave a comment:
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Re: Troubleshooting dead Apple MacBook Pro A1398 (820-00426-A)
and I dug deeper...
Found the startup power sequence and took the following measurements:
S5_PWRGD = HI
PM_DSW_PWRGD = HI
ALL_SYS_PWRGD = LO
PM_PCH_SYS_PWROL = LO
PLT_RESET_L = LO
So trying to understand what drives ALL_SYS_PWRGD to HI. Looks like U8160 voltage monitor?
P1V05S0_PGOOD = LO
P1V5S0_PGOOD = LO
Or the S0 Rail PGOOD (BJT Version)
VMON_Q2_BASE = LO
VMON_Q3_BASE = LO
VMON_Q4_BASE = LO
Also...Leave a comment:
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Re: Troubleshooting dead Apple MacBook Pro A1398 (820-00426-A)
@reformatt, thank you for your comment! Was very helpful
Cannot see any corrosion and have no reason to believe this is a result of corrosion as no liquid was spilt.
None of the inductors I can reach on the topside are shorted to ground.
I googled the MAC power sequence and found this useful state change diagram:
[url]https://logi.wiki/index.php/G3_to_S3_State_for_Ivy_Bridge_Haswell_and_Broadwell[/url]
PP3V3_SUS = 3.3275 V
PM_RSMRST_L = 3.2982...Leave a comment:
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Re: Troubleshooting dead Apple MacBook Pro A1398 (820-00426-A)
Further to my question about the computer states, I found the following:
Computer is off - S5
Computer is hibernating - S4
Computer is sleeping - S3.
Computer is on and working, S0.
So given the S5 state is for when the computer is "off", it seems that my measurements are in line with it being off...
but what drives the state change? Which signal is not getting where it needs to, to stop the computer turning on?
For info, I took the PCB out...Leave a comment:
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Re: Troubleshooting dead Apple MacBook Pro A1398 (820-00426-A)
Thanks, saw that 😊
None of the issues there have similar symptoms or match my logic board part number unfortunately.Leave a comment:
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Re: Troubleshooting dead Apple MacBook Pro A1398 (820-00426-A)
Trying to figure out why the S3 rail is dead.
U7400 is not switching the FETs
Makes sense given PP5V_S3 is 0V
Looks like PP5V_S3 is created from PP5V_S4 and the PP5VS3_EN signal
PP5V_S4 = 0V
Looks like PP5V_S4 is created from U7501 using PPVIN_S5_HS_COMPUTING_ISNS
PPVIN_S5_HS_COMPUTING_ISNS = 12.683V
P5VS4_EN = backside of PCB, cannot measure
What logic drives these power states (power button, timeouts, etc?)Leave a comment:
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Troubleshooting dead Apple MacBook Pro A1398 (820-00426-A)
Hi all, first post here looking for some troubleshooting assistance with my A1398 mid-2015 MBP.
820-00426-A
History:
Many drops but nothing before failure
Many failed kernel crashes but nothing before failure
No water damage
No indication of imminent failure
Magsafe (genuine apple 85W version) goes green then orange
The computer was asleep with the screen closed
I opened the screen but the screen stayed black and fans not spinning like it was asleep
the click pad was working but computer unresponsive to power...
No activity results to display
Leave a comment: