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submerged Macbook A2141 - no power on, no voltages

S

Sanevent

Member
I checked the following G3S voltages:

PP5V_G3S - 0v
PP1V8_G3S - 0v
PP3V3_G3S_T - 0v

PP5VG3S_EN - 0v
PP1V8G3S_EN - 0v
PP3V3G3S_T_EN - 0v

Those are the lines that I thought were important to measure.
For the SSD lines, please tell me which ones are the important ones. There are at least 100 lines that include SSD somehow and I can't quite make up which ones could be important.

I you could tell me which G3S lines are important that I did not cover, please also let me know.
 
2informaticos

2informaticos

Administrator
Staff member
"100 lines that include SSD somehow"
All of them are power rails???

You have two SSD0/1 areas, each with 3 power rails: 0.9V, 1.8V and 2.5V (pages 87 & 92).
 
S

Sanevent

Member
Thanks for clarifying.
I took the measurements and got:

PP0V9_SSD0/1 - 0v
PP1V8_SSD0/1 - 0v
PP2V5_NAND_SSD0/1 - 0v

So no power on that rails too.
 
S

Sanevent

Member
When connecting the Board will it be recognized immediately or do I need to set the board into DFU mode?
As for setting the board to DFU Mode, there are 2 ways I've read about. One method uses the assembled mac and the keyboard and the other uses the Force DFU jumper. Which way is the preferred method here ?
 
2informaticos

2informaticos

Administrator
Staff member
External switch method is the best to try with board alone on the desk.

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
Now only need to check if it is recognized in DFU.

To successfully complete DFU, battery and trackpad may be needed; requires to put board back on the shell.
 
S

Sanevent

Member
ok got it. I will try the method with the switch, mentioned in the article. Is it enough for the first test to test if the DFU_STATUS line becomes 1.8v?
I only ask because gathering a second Mac will take me until next week. My colleague has the Mac from the lab for the time being.
 
S

Sanevent

Member
I tried to follow all the steps provided by the website and encountered a problem. It is stated, that I should pull up SOC_FORCE_DFU to 1.8v.
The problem is, that neither 1V8_SLPS2R nor any other 1.8v line is active. They are all 0v so I can not pull up the FORCE_DFU line to 1.8v and could not enter the DFU state.
The SOC_DFU_STATUS pin is between 0.3v and 0.5v no matter how I connect the board.
What I could try is to put the board back in its shell and then try again, but I don't know if it's a problem with the missing shell if 1.8v is not generated.
 
2informaticos

2informaticos

Administrator
Staff member
Impossible to access DFU without 1V8_SLPS2R present.

Keep tye board alone on the desk, for test.
Do you get 3V3_G3H_RTC and PPBUS_G3H now?

BTW, F7000/1 must be soldered.
 
S

Sanevent

Member
I measured around the U7800 and found the following voltages:
LDO_CORE 1.47v
PP0V8_SLPS2R 0v
PP3V0_G3H_RTC 0v
PP1V2_AWAKE 0v
PMU_LDO3_OUT 1.8v

I also measured the input side, because i dont know which voltages are derived from which - so maybe this is helpful.
PP1V1_SLPS2R 0v
PP3V3_G3H_RTC 3.3v
PP1V8_SLPS2R 0v
 
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