Re: A2337 820-02016 - logic board + what extra hardware required for DFU?
For those who have a similar problem in the future, debug process looked like:
1. Make sure that the DFU cable isn't the issue: use R1725 to check DFU state (1.2V if true), and swap around cables until it shows in idevicerestore (if you don't have a new mac for AC2 >2.13.0).
2. To actually get to DFU from recovery, I shorted pin30 on JT400 to the adjacent ground pads with tweezers as soon as I shut down from recovery, then applied the jumper for DFU while holding the tweezers in...
Sniffy
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Last Activity: 09-11-2024, 06:48 AM
Joined: 04-03-2023
Location: Taiwain
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A2337 820-02016 - logic board + what extra hardware required for DFU?
Hi,
Here's what I've got:
a2337 logic board (bom variant 639-11766) from late 2020 m1 air
USB-C I/O 821-01658-A ribbon
(no battery, dc-charger, keyboard, touchID, screen, or power button)
[B]WHAT WORKS:
[/B]Recovery and fallback recovery
HDMI output
USB mouse/kb input
DFU mode detection on other devices
[B]WHAT DOESN'T WORK:
[/B]No bootable volumes detected
Can't get to DFU (boots straight to recovery on power via usb-C) even with SOC_FORCE_DFU pulled to 1.8V via short (per wiki), or... -
Re: M1 A2337 Not able to access Recovery or DFU mode
Hm, ok that's interesting. So DFU recovery worked in the sense that you did a complete restore? or you didn't erase/restore it?
There should be both recovery and fallback recovery after you reinstalled I think (2019 copyright vs 2021 copyright in the about menu), but if the recovery volume is missing then you wouldn't be able to boot to it (not sure about internet recovery though).
I need to see if I can get a low-health battery cheap locally if that might be the issue... the one that...Leave a comment:
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Re: does anyone know how to convert a clevo laptop to UMA graphics only?
Would this method potentially be safe to work on a p75x-dmx?
I toasted the mxm card in mine a few years back and it's just been sitting on a shelf since then......Leave a comment:
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Re: EBC-820 "Apple diagnostic tool" -- does this work?
SWD or DSCD cables? I know it's a legal grey area tho......Leave a comment:
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Re: New Members - please post your introductions here
Hi,
I go by Tony, and I've got some experience, mostly smps and high power (5kW+) PWM/PDM drive for RF applications on the analog side, and used to be active on NBR before they shut down. 3d Mark overclocking hall of fame member before it became a wallet stress test...
Excited for apple silicon (after holding out for too long), but need some help with the very closed hardware ecosystem, maybe I can share some help for older (1st and second gen intel lol) bios modifications or overclocking tips.
...Leave a comment:
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Re: M1 A2337 Not able to access Recovery or DFU mode
Reading the schematic, it seems like SOC_FORCE_DFU is pulled up to 1.25V via a 1kOhm resistor in the schematic/boardview (clipped to the imgur link below), rather than pulling straight to 1.8V... but I really don't know.
imgur OZmQL9t
The issue might be that I don't have a keyboard/screen/touchID/battery/IO board connected aside from a usb charger or DFU cable.
Board boots fine straight to recovery after nand swap, but it doesn't see any volumes at all (idk if...Leave a comment:
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Re: Macbook Air A2337 external display
Thanks for the advice! I ended up just shorting IPD_LID_OPEN_1V8 to ground on JT400 with tweezers since I don't have a chassis attached (same as the OP here).
Right now I'm trying to get to DFU (also without a display, keyboard, touchID, battery etc attached) if that's even possible......Leave a comment:
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Re: Macbook Air A2337 external display
Did you ever figure this out? cmd+f1 and cmd+f1+1 aren't doing anything for me...Leave a comment:
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