MacBook Pro13 A1706 only no CPU Rail

[SVAudio]

Hello everyone,
I received a MacBook Pro 13 inch from a friend for repair
Model: A1706 820-00239
The device shows no reaction to the power button,
no water damage, no optical problems, nothing noticeable.
It was closed working and since then it has been dead.

I have already checked the following:

1) With battery connected:
Charging via USB-C on all 4 ports OK Voltage PPDCIN_G3H goes to 20V, PPBUS_G3H to 13.1V.
2)Further measurements without battery and other components except USBC power supply

PPDCIN_G3H 20,0 V
PPBUS_G3H 13,1 V
PPBUS_HS_CPU 13,1 V
PPBUS_HS_OTHSV 13,1 V
PPBUS_S4_HS_TPAD 13,1 V

PP3V3_G3H 3,3 V
PP3V3_G3H_SMC_ISNS 3,3 V
PPVCC_S0_CPU 0,0 V (7 Ohm to GND)
PPVCCSA_S0_CPU 1,0 V
PPVCCGT_S0_CPU 0,0 V (2,7 Ohm to GND)
PPVCCIO_S0_CPU 0,95 V

PPVCCEDRAM_S0_REG_F 1,05 V
PPVCCEDRAM_S0_CPU 0V (55 Ohm to GND)
PPVCCPRIMCORE_SUS_PCH 1,0V

PP0V6_S0_DDRVTT 0,6 V
PP0V6_S3_MEM_VREFDQ_A 0,6 V
PP0V6_S3_MEM_VREFCA_A 0,6 V
PP0V6_S3_MEM_VREFDQ_B 0,6 V
PP0V6_S3_MEM_VREFCA_A 0,6 V

PP1V8_SUS 1,8 V
PP1V8_S4 1,8 V
PP1V8_S3 1,8 V
PP1V8_S3_MEM 1,8 V
PP1V8_S0 1,8 V

P1V0_SUS 1,0 V
PP1V0_SUSSW 1,0 V
PP1V0_SUSSW 1,0 V
PP1V0_S0SW 1,0 V

PP5V_S5 5,0 V
PP5V_S4 5,0 V
PP5V_S0 5,0 V

PP3V3_S5 3,3 V
PP3V3_SUS 3,3 V
PP3V3_S4 3,3 V
PP3V3_S4_BT 3,3 V
PP3V3_S4_TPAD 3,3 V
PP3V3_S5_SSD 3,3 V
PP3V3_2V7_NAND_VCC 2,7V
PP3V3_S4_SOC_PMU 3,3V

ALL_SYS_PWRGD: 3,3 V -> OK

I then took a closer look at the CPU power supply:
PP5V_S0_VCORE1 5V
PP5V_S0_VCORE2 5V
PP5V_S0_VCCSA 5V
PP5V_S0_VGT1 to 3 all 5V
PPVIN_S0_CPUVR_VIN 13,1V
PP5V_COREVR_VCC 5V

CPUVR_PGOOD 0V

Does anyone have a tip for me where I should look further?
The clocks 32k and 24MHz... are also there

Unfortunately it's my first attempt at MAC repairs, I usually do more digital audio devices
I am therefore grateful for every help

Greetings from Germany Stefan

[reformatt]

Re: MacBook Pro13 A1706 only no CPU Rail

What about PPVCCSA_S0_CPU? Check closely around the sides of U7100 for contamination or corrosion too. Depends on where it lands....sometimes you get lucky and it just kills the drive. Other times, you end up with shorted MOSFET's and a dead CPU.

Corrosion on MAC's is quite often small and easy to miss, so look carefully under a microscope. It can be something as small as a dead insect whose decaying corpse shorts out a cap etc.