Im starting to think aswell that USBC is kind of messed up, especially in MacBook with a power sequence longer than my arm.
what do you think of draining the battery as much as possible to a point where the trackpad wouldn’t even click and the battery icon would stop showing up (by repeatedly pressing keys for example) and then plugging it to power ?
mon2
i ordered an infiray P2 Pro. It’ll help for future repairs, and maybe with my own Mac too....
Gueric
Senior Member
Last Activity: Yesterday, 02:46 PM
Joined: 02-10-2025
Location: Rouen, Normandy
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MacBook Pro 820-02020 Weird behaviour
Hey mon2, it’s me again. My Mac worked fine a full week, then did the same thing again. Charger would not do anything once plugged in, and battery wouldn’t charge. It’s currently drained,
And only reacts/shows a charging icon when plugged into the top port (slave CD3217, that I replaced 6 months ago). Plugging it in the master port doesn’t do anything.
the trackpad clicks for some reason, even with the charger unplugged.
despite hearing the charging chime and leaving it like that for a while it’s still showing this charging icon. I don’t have access... -
Hey mon2 this might help you with your pile of MacBooks so I thought I’d share.
I’m still trying to figure out why this M1 shuts down randomly after a few minutes/hours.
im currently doing a test, which consists in playing a 10 hour video non stop WITH THE POWER ADAPTER PLUGGED IN.
its been almost 24 hours now, zero bootlooping or unexpected shutdowns so far.
i might do the same but on battery power to rule out a defective battery (even though macOS tells me its in normal condition)
I reckon that would explain the random shutdowns...Leave a comment:
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I might try to do this. Unplugging audio board, maybe speakers etc… but in my case it does not bootloop while reinstalling macOS and while browsing the recovery options. Has this specific case ever happened to you? Right now I’ve erased the whole disk, reinstalled the OS, and created a random account.
im pretty sure its gonna bootloop again tonight but its tricky to know why.
I’m wondering if this 100 ohm PP3V8_AON has anything to do with that. Anyway, thanks mon2...Leave a comment:
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Okay so. mon2 it is still bootlooping for no reason at random moments. It installed macOS Sequoia fine etc, then started bootlooping on the Apple logo again. For some odd reasons, starting into the recoveryOS doesn’t make the laptop bootloop. I can even navigate the startup options like disk info etc…
Do you have any idea what might be
happening ?...Leave a comment:
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mon2 I’m using the same power adapter always, but it’s a cheap 100W unit. It hurts to pay this much but I should buy a proper Apple unit.
back to the laptop. I did a full wipe, and it worked, charged every single time. Disconnected the battery, put every screw back on, plugged the battery back in, started to go crazy again. Would bootloop every time I tried to enter the password.
i then tried to DFU it, I managed to enter DFU and start the process but it kept rebooting and tried to boot into the OS while the process was underway.
The DFU obviously...Leave a comment:
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Hey mon2.
For some crazy reason im having the exact same issue i had with my own macbook a few days ago. I decided to put the board back together, boot it up, and it instantly negotiated 20v. It booted fine, no more bootlooping. But the behaviour is inconsistent now. Sometimes 20v at 0.00A, sometimes 5v at 0.42A, and sometimes normal behaviour = 20v and a few amps, charging battery.
im currently reinstalling macOS to see if it might solve the issue....Leave a comment:
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also, I checked SOC_DFU_STATUS and it's around 1v. does that mean it's in DFU mode and that would explain the 5V instead of 20? I don't know much about itLeave a comment:
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mon2 PPBUS_AON is a stable 12.01v.
i remember i tried to replace a second time the CD3217 just in case and nothing changed.
i agree with you on PP3V8_AON, but is it fine even if lts 100 ohm as i said? It is 3.8v as expected so i guess its fine as you said...Leave a comment:
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A2338 820-02020 5v 0.04A PP3V8_AON low
Hey mon, its me again (sorry) so after fixing my own Mac I’m back to try and fix another one.
I changed a CD3217 on this one. And it started bootlooping a few hours after the fix.
5v, 0.20-0.30A for the first few seconds then drops to 0.00-0.05A.
PPBUS_AON is 12v.
PP5V_S2 is present.
PP1V25_S2 is present.
PP3V3_S2 is present.
PP3V8_AON is 3.8v, but its diode mode was abnormally low (.150v instead .350v)
And to make it even worse I accidentally touched PPBUS and 3V8 with my meter and the resistance is now 100 ohms (don’t... -
Okay so mon2 i let it sit for around 3 hours, until the current draw dropped to 1A. Upon opening it it seemed to have been completely corrupt somehow, my password wasn’t recognized, keyboard was misbehaving, and after going into the startup options it couldnt speak with apple Activation servers. I had to manually erase the mac to get it to activate, and now it’s currently reinstalling MacOS. Oh my freaking god.
and still one of the 2 ports isn’t working at all now. Crazy. If the Mac fully works ill stick to just 1 port....Leave a comment:
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Some news again… mon2
So the CD3217 port i replaced originally is now rebooting sometimes, and the other port works but only in 1 orientation and doesn’t reboot.
so i decided to put the machine back together. It is pulling 20v and 2.4Amps, so way better.
tried powering it on, it works, but acts strangely on the login screen. After a few seconds on the login screen, it reboots, boots to the login screen, and 5 seconds after reboots again. I really don’t know what to do at this point this whole thing is about to make me quit
right now i turned the...Leave a comment:
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Sorry important correction : PPDCIN_CHGR_CHGR_R is around the same voltage as PPBUS_AON when plugged in the bad way (around 2v, dropping fast)
measuring on the fuse just next to the CD3217s never gives me more than 100mV. (When plugged in the bad way into the master CD32)
okay some news… what the hell.
Both ports randomly decided to negotiate 20v again?
still, on the master CD3217 ports, it won’t work when plugged the « wrong » way. But the other way it does negotiate 20v aswell. Bruh. All I did was heating the master CD3217 for a few seconds at 150c then waited...Leave a comment:
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Also, it’s a standard M1 Pro from 2020. Only 2 ports and thus 2 CD3217s.Leave a comment:
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Hey mon2 im back. I did a few measurements, and tried measuring voltage with the misbehavingCD3217 plugged in. When plugged in the way that doesnt even turn on the ampmeter, measuring PPDCIN_USBC_AON gives me 0v. PPBUS_AON gives me around 2,7v then slowly drops below 1v overtime. PPDCIN_AON_CHGR_R give me a few milivolts at most.
I think I’m with you on this one. I tried cleaning the port as best as I could, try with a different USBC flex cable, nothing worked.
honestly I don’t have enough experience to point at anything except this master CD3217 chip. Thankfully...Leave a comment:
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Okay well you were right. The board behaves exactly the same no matter the port and USBC orientation EXCEPT for one orientation, when plugged one way into the master CD3217 (the one i didnt replace). The ampmeter doesn’t even turn on and PPBUS is 2.7v, dropping to 1.5v after a few seconds. Tried without the ampmeter and same result. Boards works with 3 out of the 4 possible « connections» Turning the USBC around makes it work fine.
What does this even mean? Is it a CD3217 issue or something else ?
also some details : i never replaced the master CD3217. I replace the...Leave a comment:
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mon2 are you sure a CD3217 could be defective if the Mac fully works except for the « battery not charging » part ?
Even though yes, it’s stuck at 5v, but it negotiates 20v at first when plugged in for the first few seconds and drops to 5v when interacting with it (pressing any key or even the trackpad)...Leave a comment:
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PP1V8_S2 is exactly 1.800v.
PPCHGR_VDDA and PPCHGR_VDDP are both 5.175v.
Resistance across C5221 and C5222 is 02.75 ohms.
By the way, if that can help, even though the board is working fine at 5v and no charging, bare board pulls 5v and 190mA, then drops to 0.00A after 2-3 seconds.
and originally this Mac had a defective slave CD3217 (might not be relevant to this charging issue, but I wanted to add this detail)
thanks mon2 :-)...Leave a comment:
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Macbook Pro M1 (A2338) 820-02020 not charging.
I returned home from college. My MacBook battery was flat. Plugged it in. Nothing. Won’t boot. Waited for an hour. Nothing.
When plugging the charger : 20v at 0.02 amps.
pressing any key will make the « low battery » icon show up. Then switch to 5v and 420mA constant. Trackpad clicks, keyboard works.
Decided to put the board into another M1 body with a charged battery, it’s booting perfect, still 5v and 420mA tho, and battery is not charging.
I diode moded every pin of U5200 and they’re all fine. I know very little about Apple silicon machines... -
hey mon2 i found that short by injecting voltage again. i had to step up to 3v for it to show. small cap drawing 2v at 5 amps, literally smoking. @C7401. now i gotta put every component back on and pray. By the way, do you know if SW6955 if compulsory for the board to boot? i think i damaged it while removing Q8100. its SYS_DETECT and GND....Leave a comment:
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