Yes, ppbus MUST be stable and present. I would make sure you soldered the nands properly/completely. If DFU completed successfully, the nands should be ok. So, I would also suspect and inspect the SSD controller ICs. Remove the bridge resistor for PPBUS and SSD power to see if ppbus stabilizes. If so, then you have an issue with the SSD power ICs, but again, that would typically prevent DFU restore from completing.
You "MIGHT" have a damaged T2; confirm all SLP/AWAKE voltages are stable and not pulsing after 20 seconds.
ugamazing
Senior Member
Last Activity: 03-01-2026, 07:22 PM
Joined: 06-26-2013
Location: georgia
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Yes correct, it must be programmed. It's still part of the "old" SSD at this point.Leave a comment:
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You need to focus on DFU mode right now; if you can't enter DFU, we need to figure out why.
What are your T2 voltages? SLPS2R & AWAKE....Leave a comment:
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Specific Data-Recovery Assistance on no-power 820-02536 (A2681)
Received this unit for data-recovery only. Unit has no power and charger cycles the instant it boosts to 20v on all ports. Unit will show life when REVIVING, but fails DFU eventually (expected DFU mode, i.e. a cycle/restart of SOC). Board and unit are super clean, I suspect the unit may have simply lost power at a critical point of update. Customer doesn't care about repair, only wants data. But I strongly feel a restore is what the unit needs. Again, during revive, video will show on LCD, but there is never any trackpad click (I'm unsure if there is normally anyway at this specific point, reviving... -
A1990 and A1707 batteries not cross-compatible. Just mentioning that because you mentioned them both as if they might be.Leave a comment:
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Hey this is way way late, but I randomly came across this thread: These boards used a ton of different T2 chip models, and they varied by RAM cfg. The 16GB boards use a different T2 model. If you upgrade the RAM, you have to upgrade the T2, which is of course not worth it in the vast majority of cases.Leave a comment:
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Thank you so much, Pedro! We all really appreciate it....Leave a comment:
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Any change in behavior with safe boot? I imagine now, but just in case. Most likely GPU or VRAM yes. Run MEMTEST also just in case.Leave a comment:
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bastien
Thank you for all your hard work, it's much appreciated! Would you by chance be able to re-upload this program file? The forums experienced a breach/failure and it deleted all uploaded files....Leave a comment:
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I've heard from a few people that there is one single solution to MDM/DEP enrollment locks, but it's not an easy fix: You can ENROLL the affected device(s) into your OWN DEP/MDM server/account, and it will apparently remove the pre-existing DEP/MDM. You will have to get an enrollment account to do this, however.
Otherwise there is no fix. DEP/MDM locks based on serial which are written in the CPU/WiFi, which are not economical to replace (at that point just swap the board out)....Leave a comment:
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Thanks, Flea!! Had no idea there were still issues being worked on, thank you for the update! We appreciate you guys....Leave a comment:
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The forum crash deleted a bunch of files; we'll need people to re-upload, so hopefully they see the notifications and will do so for us. Thanks for all people who continue to upload schematics!Leave a comment:
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Is PP1v8_SLPS2R shorted? It should be stable. Might be a faulty T2. Are other T2 rails stable or do they all cycle?
Also, the change in PPBUS when disconnecting battery is unusual; ppbus will be lower on battery and higher on charger(+batt). Have you tried testing board with a known-good case/battery and also DFU restore?
What work has been done on the board if any? Any signs of damage/liquid near any USB-C controllers at all? 20v/0a can be a ROM issue also, keep in mind. You can swap the ROM or reprogram with clean dump to be sure.Leave a comment:
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Any chance we can get these files re-uploaded? I think the forum crash last week took them out.Leave a comment:
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A2159 CPUs are trash, might be a failing CPU. Of course, messing with ROM will create unusual issues, but since you mentioned restore issues beforehand, it's possibly a failing CPU. T2 could be suspect, but it typically won't be affected by safe/non-safe boot conditions (as its work is largely 'done' once power is achieved).
Try reflowing the CPU and the RAM and see if conditions change. Sometimes you get lucky on these.Leave a comment:
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Glad you got it sorted! Very common issue a few years back as many parts vendors did not specify or differentiate 2020/M1 vs 2022/M2. Lot of headaches for retail guys.Leave a comment:
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To confirm...you're using a proper 2022 M2 A2338 trackpad/cable and NOT a 2020 A2338 M1 trackpad/cable, correct? Check part numbers to confirm. Big issue with parts vendors.Leave a comment:
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You can find good chips there, but you'll also find bad ones. Best to source from a parts board if you can; the 02020 boards can have the controllers replaced individually if you pull from the same model/etc. There are plenty of good sellers on eBay for chips as well!Leave a comment:
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Hey Mon, I sent Piernov a PM a week ago and haven't heard back. I wonder if it didn't go through?Leave a comment:
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