(Solved )820-02020 stuck at apple logo

[thiben]

Hello ! Im new here and glad to be here ! Ive here a Macbook M1 a2338 820-02020 ! The problem is that he stuck at Apple logo then vome progress bar load 10 15 % and restart ! The board have no water damage and no corrosion ! Its look like new !
Ppbus_aon is 11.99 Volt and fluctuate every 25 sec to 12.28 Volt ! diode mode 0.496 !
Pp3v8_aon is 3.8 Volt 0.150
Pp5v_s2 is 5.1 Volt 0.303 !
Can you help me ? Thank you very much !

 

[2informaticos]

First of all, welcome to the forum!

You should try DFU revive.
If no data to save, go for restore directly.

 

[thiben]

Hi 2Informaticos ! Thank you very much !
I already try dfu mode but dont work !i have the black screen when the MB goes in DFU but AC 2 from Host didnt see the MB ! Wenn i try safe mode too it restart too !
I read that we can force DFU with some jump or something like that ! Will try with SOC_FORCE_DFU with 1.8 v !

 

[thiben]

So i inject 1.8 v in SOC_FORCE_DFU then i get
The signal SOC_DFU_STATUT high with 1.2 V !
But is not recognized im Host MB …

 

[2informaticos]

Did you follow all the steps in DFU tutorial?
Be sure to use the proper port and try another cable too.

DFU Mode Restore (Macs) - LogiWiki

We have Apple MacBook and iPhone Diode readings and general fault finding information compiled by the leaders in this area

logi.wiki

 

[thiben]

I follow exactly this ! But why i get only 1.2 V on soc_dfu_status ? It schould be 1.8 V ! That why i think isnt detected with the Host MB !

 

[2informaticos]

I just saw that you've injected 1.8V into SOC_FORCE_DFU.
How and why???

Solder RV005 and use SV004/5 pads.

Why do you expect 1.8V there, if this is M1 machine (not T2)?
Pay more atention looking at schematics.
M1 uses 1V25 line for this purpose!

 

[thiben]

Hi Informaticos ! Sorry i thoug i have to inject 1.8 V ! Sorry ! Just want to say its worked with dfu mode ! Many thanks informaticos !