Re: MacBook Air A2337 - 820-02016 - Stuck at 5v - Varying current draw - Board had sh
Ok, so I have now replaced U8100, and U5700, as well as both of the CD3217's from the working donor, and no change at all in behaviour.
Still stuck at 5v, with
PP3V3_S2_UPC pulsing,
PP5V_S2: 0v
PP1V25_S2: pulsing
P5VS2_EN : 0v
What else could be causing being stuck at 5v?
duwane
Senior Member
Last Activity: 04-09-2025, 07:19 AM
Joined: 03-05-2022
Location: Auckland
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Re: MacBook Air A2337 - 820-02016 - Stuck at 5v - Varying current draw - Board had sh
Found something else that may or may not be related. When testing resistance to ground between working donor and faulty board, I get some wildly different measurements around U5700.
For example:
[ATTACH]314823[/ATTACH]
Resistance to ground, and diode mode to ground at the highlighted test point (PP5907) on both boards:
Donor Board: 267 Ohm -0.131v diode mode to ground
Faulty Board: 380k Ohm - 0.324v diode mode to ground
[ATTACH]314824[/ATTACH]...Leave a comment:
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MacBook Air A2337 - 820-02016 - Stuck at 5v - Varying current draw - Board had short
Hi All.
I have an 820-02016 board (A2337 M1) that has come in for data recovery. Reported as liquid damage, but no visible evidence of any liquid damage.
Board was initially stuck at 5v, and current only spiking occasionally to around 400mA and cycling.
After initial troubleshooting, found that C7800 (which feeds the power rail PP5V_BSTLQ_VOUT_SPMU) was dead short to ground.
Replaced C7800 and short gone. Board still stuck at 5v. Current draw behaviour changed. It now spikes up for a second to around 100mA to 130mA, then drops down to...Last edited by duwane; 10-17-2023, 08:10 PM. -
Re: A2251 (820-01949 board) PMU IC U7800 CALPE-PMU
Thanks Mon. I will try both of those and feed back in this thread....Leave a comment:
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A2251 (820-01949 board) PMU IC U7800 CALPE-PMU
Hi All.
I have an A2251 820-01949 board that has come to me for data recovery. Previous repair shop that worked on the board have removed the PMU as they said that the chip had a hole burned into it. I have replaced a bad cap that was causing a short on PP3V3_G3H_PMU_VDDMAIN to ground that I am 99% sure is what caused the PMU to blow. Now I am trying to find a replacement PMU chip U7800 (labled as "CALPE-PMU" in the schematic).
I have several questions about the PMU chip itself:
1) Does anyone know if these chips are identical between boards... -
Re: A2141 (2019 16" MB Pro) Strange macOS install issues. NAND? WIFI? FIRMWARE?
To me the 2 most important lines in the Ventura log are:
Does that not imply that it was unable to update some firmware? The installation seems to halt right after that.
And the most important lines in my opinion from the Catalina logs:...Last edited by duwane; 10-26-2022, 07:20 AM.Leave a comment:
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A2141 (2019 16" MB Pro) Strange macOS install issues. NAND? WIFI? FIRMWARE?
Hi All.
Sorry ahead of time for the text wall. This is a strange problem and I have tried to explain it as best I can. I realise this is a hardware forum (mostly), but I am still not sure if this is even a hardware fault! I am hoping that someone more knowledgeable than me in the area of understanding installation logs, or someone that has had a similar issue in the past may have some ideas of what might be causing this.
[B]The issue:[/B]
Unable to do a clean install of any macOS versions supported for this model, even after fully erasing and formatting the internal...Last edited by duwane; 10-26-2022, 07:04 AM. -
Re: MBP 16" A2141 - Cannot install OS
I have this exact same issue with the same board at the moment.
I know this sounds crazy, but the fix is to change the DNS server in the DHCP scope that the machine is getting its DHCP lease from. The DNS server I used is 1.1.1.1
When you change the DNS, the installation will continue as normal. At least it did for me, but there is definately something about this error that points to a timing issue with the networki/wifi side of things.
Let me know if this helps you out, as it would be good to know...Leave a comment:
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Re: Macbook A2337 820-02016 Backlight Issue
I don't know the layout of this specific model's board, but use a paperclip or other small metal object on the edges of the screen to find where the the magnet is located, then the hall sensor will be in the corresponding position on the logic board.
That depends on how the seonsor fails.
Are you sure its just a backlight issue? Have you confirmed you actually have image? Tried external monitor?...Leave a comment:
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Re: Macbook A2337 820-02016 Backlight Issue
Hall sensor issue maybe? Check for corrosion and continuity around that area, and make sure the hall sensor is working as it should by bringing a magnet close to the sensorLeave a comment:
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Re: MacBook Air 2018 A1932 820-01521 Not turning on.
What machine are you running the configurator software on? I had something similar with a 1932 that I restored.
I know that Apple's information gives a minumum version of software of like Catalina or something similar, and says you can use any machine to run configurator on, but I found I needed a machine that had only USB-C ports, and ran the latest patched version of MacOS available for the machine I was using.Leave a comment:
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Re: 820-01958 - Missing PP3V3_S5 - No liquid damage
Quick update for anyone coming to this in the future. I ended up fixing this device. Corrupt firmware was stopping PP3V3_S5 from being produced by the PMIC.
I was getting DFU failure error 4014 when trying to revive or restore the machine from a host laptop running Catalina using a USB-A to USB-C cable.
I tried several cables, but all failed with the same error. I was about to give up, but tried one last thing. I then ran Apple Configurator 2 on a machine running Monterey, and used a usb-c to usb-c...Leave a comment:
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820-01958 - Missing PP3V3_S5 - No liquid damage
Hi All.
I have an 820-01958 T2 board from a 2020 A2179 that does not want to boot.
No visible signs of any liquid damage. Green/orange light is present on charger, and switches over to 20v (unless I plug a battery in, then it doesn't switch and stays at 5v). Not sure this if the battery issue is relevant to not booting though as battery does not appear to charge, so could just be a faulty battery.
Right after negotiation happens from 5v to 20v, board draws around 180 - 250mA, then settles between 30 and 45mA thereafter where it stays.
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Re: KB and Trackpad only work in safe mode - 820-4924-A Macbook Pro Late 2015 A1502
Fair enough. I hadn't thought about it that way. You are correct as I tested typing before plugging in the HDMI cable, and I can see what I have typed after plugging in the HDMI.
Sadly I tried replacing the LVDS cable, and the problem persists, so sounds like it is destined for the scrap heap....Leave a comment:
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[SOLVED] Re: KB and Trackpad only work in safe mode - 820-4924-A MBP Late 2015 A1502
So I have managed to solve this issue, and thought it would be good to come back and update in case anyone has a similar issue in the future (as this thread seems to come up first in Google for searches for this type of issue with this board number).
I managed to get hold of another 2015 A1502 with known good keyboard, trackpad, and screen. Swapped the "faulty" board into the chassis, and problem was resolved, and everything works as it should. After swapping out screens,...Last edited by duwane; 06-06-2022, 12:39 AM.Leave a comment:
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Re: KB and Trackpad only work in safe mode - 820-4924-A Macbook Pro Late 2015 A1502
Sorry, badly worded. What I meant was only the cursor locks up, meaning when I move on the trackpad nothing happens (cursor doesn't move).
When I play a Youtube video, if I unplug the HDMI cable while it is playing, it carries on playing and the keyboard and mouse continue to work. When the video ends the keyboard and mouse stop working again.
Could it be power saving related somehow? I have checked the hall sensor, and that works....Leave a comment:
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Re: KB and Trackpad only work in safe mode - 820-4924-A Macbook Pro Late 2015 A1502
So after letting this sit for a while, I finally got back to it and did some more testing.
If I plug an external screen/TV in via HDMI, everything springs to life. The keyboard and trackpad start working, and also external keyboard and external mouse start working. If I unplug the HDMI cable, everything works for a few seconds, then trackpad and keyboard (and external keyboard and external mouse) stop working again and cursor just locks up. Caps lock key still works on KB however. ...Leave a comment:
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Re: Apple 85W MagSafe Power Adapter - blown - help with component identification
Just did a brief check through it, and found the following section (see image) which pretty closely matches the section of the circuit that I am trying to find the value for the burned resistor.
I think a value of 0.18ohm for R051 in my case (R26 for the A1424) is what I am going to go with, as my gut feel was 0.17ohm based on what I could still idntify from the resistors burned marking. Thanks again foir posting this!...Leave a comment:
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Re: Apple 85W MagSafe Power Adapter - blown - help with component identification
Awesome thanks. I will check through this and see how much of it is accurate for the A1343....Leave a comment:
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Re: Apple 85W MagSafe Power Adapter - blown - help with component identification
Sorry, only just saw this. It connects to pin 13. I have taken another photo now that I have removed the 2 resistors, the FET, and the IC.
There was some sort of hard underfill in a circular blobs under the chip which I can't remove, so its not so clear or easy to see. Sorry. The exposed tracks were underneath the fill....Last edited by duwane; 06-03-2022, 11:55 PM.Leave a comment:
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