Missing PP3V3_S5 on A2141 board 820-01700

Hi there, I am from Mexico and I living in Morgan Hill California, my first language is Spanish so my English is not that good, so sorry for my grammatical.



I am fixing a mac book pro model A2141, the motherboard model is

820-01700

At first when I connect the USB-C charger the voltage was only 5v, then

I check the pin VIN_3V3 C20 on U3100 line

PP3V3_G3H_RTC_X = 0 volts



PP3V3_G3H_RTC_X is provide by U6940



Checked EN E4 line on U6940

CHGR_EN_MVR_R= 0.5 v, too low to work ok



Check CHGR_EN_MVR for shorts but its ok



CHGR_EN_MVR_R coming from U7000

Check all voltages in U7000, everything its OK but CHGR_EN_MVR its low voltage

Then I replaced U7000



U7000 replaced and now I have 20.15 v and 0.032A to 0.036 A on the input but MacBook don’t start



PP5V_S4_X_USBC = 0v

UPC_X_5V_EN_R = 0V

PM_RSMRST_L = 0V

UPC_X_5V_EN = 0V

PP1V8_SLPS2R = 1.8V

PP3V3_S5 = 0V

PP3V3_G3H_SOCPMU = 3.36v

PP1V8_SLPS2R_PMUVDDGPIO = 1.8v

PMU_VDD_HI = 12.62v

PVCCPRIMCORE_SW0 = 0v

PVCCPRIMCORE_SW1 = 0v

PVCCPRIMCORE_FB = 0V

PPVCCPRIM_FETIN = 0V

Check all these lines for shorts but they are ok, specially the line PP3V3_S5 = 0V

Do I need to replace U7800? This U7800 can be purchased new or I need to get it from a donor MacBook? Thank you very much for your support.
 

2informaticos

Administrator
Staff member
First of all ¡bienvenido al foro!

As a basic step for T2 machines, try to put in DFU mode.
If can't do it, check if all AWAKE and SLPS2R voltages are present.
If can see it in DFU but can't complete the process, then check if all SSD voltages are present.
 
Ok, i tried to put it in DFU mode but 2 seconds later comes back to the screen that says connect devices, then 8 seconds later it tries to connect but again comes back to the same screen and repeat the same

AWAKE VOLTAGES

PPVDDCPU_AWAKE = 0.75V
PVDDCPUAWAKE_SW0 = 0.75V
PVDDCPUAWAKE_SW1 = 0.75V
PVDDCPUAWAKE_SW2 = 0.75V
PVDDCPUAWAKE_SW3 = 0.75V
PVDDCPUAWAKE_FB = 0.75V
PVDDCPUSRAMAWAKE_SW0 = 0.8V
PPVDDCPUSRAM_AWAKE = 0.8V
PVDDCPUSRAMAWAKE_FB = 0.8V
PP3V3_AWAKE = 3.37V
PP1V2_AWAKE = 1.19V
PP1V2_AWAKE_SOC_PLLCPU_F = 1.19V
PP1V2_AWAKE_SOC_PCIEREFBUF_F = 1.19V
PP1V2_AWAKE_SOC_PCIEPLL_F = 1.19V
PP1V2_AWAKE_SOC_PLLSOC_F = 1.19V
PP1V2_AWAKE = 1.19V
PP1V8_AWAKE = 1.8V
PP1V8_AWAKE_SOC_FMON_RC= 1.8V
PP1V8_AWAKE_SOC_TSADC_RC= 1.8V

SLPS2R voltages

PP0V8_SLPS2R= 0.8V
PP1V1_SLPS2R= 1.1V
PP1V8_SLPS2R= 1.8V
PP1V8_SLPS2R_SOC_LPADC_RC= 1.8V
PP1V8_SLPS2R_SOC_LPOSC_RC= 1.8V
PP1V25_SLPS2R_SMC_AVREF= 1.25V
PP1V8_SLPS2R_PMUVDDGPIO= 1.8V
PP1V25_SLPS2R_SMC_AVREF=1.25V
 

2informaticos

Administrator
Staff member
AWAKE and SLPS2R voltages look good; if steady, of course.

Don't worry, you will understand in time what you need to measure and what not.
Is normal to waste some time at the beginning, with irrelevant checkings.

Did you exactly follow the steps in DFU tutorial linked on the forum?
Be aware at the connection cable quality.
 
question : PP5V_S4_X_USBC= 0v, its provided by L3500=0v and coming from U3500, UPC_X_5V_EN_R enable U3500 and is 0 v, this is normal?
 

2informaticos

Administrator
Staff member
"Will not appear, until an USB device is detected, on the corresponding port."
Do I need to write in capital letters?

That voltage (as LB700 too) is for power up external USB device, WHEN is detected!!!
Each coil serves for one pair of USB-C ports.
 

2informaticos

Administrator
Staff member
It is controlled by T2.
May not appear, if T2 is not able to control power on sequence.
This can be a result of T2 firmware corruption.
Is the reason of DFU attempt.
 
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