(347) 552-2258 [email protected]

M1 Macbook Air 820-02016 not going 20V, cycling USB-C.

U

user54321

New member
Hello!

New to this forum, but have almost same symptoms on 820-02016 board as BLS951 had.
This one does 5V 200mA for a short time, then goes down to ~40mA before shutting down and starting the cycle anew (USB-C multimeter).
Measured the mentioned points:

PP3V8_AON_VDDMAIN - ~3.8v
PPBUS_AON -12.3V then 12.0V and going down during reset
PPVDD_SOC_S1 - ~0.67v
PP1V8_S2 - ~1.8v
PP2V5_AWAKE_NAND - 2.5v
PP1V25_S2 - 1.22v
PP3v3_S2_UPC - 3.28v
PP5v_S2 - 5.2V
PP3v3_UPC0_LDO - 3.25v
PP3v3_UPC1_LDO - 3.25v
PP1v5_UPC0_LDO_CORE - ~1.5v
PP1v5_UPC1_LDO_CORE - ~1.5v
Voltages are the same as in his post, basically down to multimeter variance.

All measurements taken with board outside the chassis, nothing else connected.
I found this rewa video and was wondering if it was this issue?

Their voltage and amp reading are kinda off, due to them using some weird 20V -> USB-C adapterbrick.

 
2informaticos

2informaticos

Administrator
Staff member
First of all, welcome to the forum!

Corrupted USB-C ROM can cause this failure.
Apart of necessary tools, you need correct dump for the chip.
Remember to make backup first.

You should try first the board with known good battery...
 
U

user54321

New member
Thank you for the warm welcome!

Only issue with testing with known good battery would be the fact, that we currently do not have another device of this type or a known good battery for it. Is there a way to check if the battery we have is good? (we do have NLBA Battery analyzer)

Would obviously make backup, unfortunately however i couldn't find another source for the DUMP, but do not want to buy REWAs special programmer just for the dump of this one chip.

Any recommendations?
 
Last edited:
U

user54321

New member
Thank you very much!
It was indeed the firmware chip itself (UF260), i tried reading it with both our XGecu Pro TL866II Pro and our RT809F, both would not identify it properly, and manually setting to the correct W25Q80DV setting revealed the content to be empty (all 0xFF) using a donorboards(820-00875-A) W25Q80DVUXIE (backed up the firmware just incase we might need it someday) and flashing the provided file worked great!
It now goes to 20V and boots up just fine.
Still have the feeling some things are a bit wonky, but i suspect the empty battery to be the cause, so will keep it plugged in and charging on lockscreen for a bit.

Many thanks again and a good day to you!
Best regards
 
Last edited:
2informaticos

2informaticos

Administrator
Staff member
Thanks for feedback solution.
We don't have to much information for M1 boards.
Someone else wil find this useful in the future.

BTW, write directly into reply box, instead of clicking Reply button.
I don't see any reason to quote an entire post, visible few centimeters above.
Please, mainatin forum aesthetic...
 
You must log in or register to reply here.
Top