820-02100 charging pulsing..

[yair37]

U8100:
PP1V2_S2 1.2v
All the rest is 0v

U7700:
PP1V8_S2 1.8v
All the rest 0v

No short found.

 

[2informaticos]

Check U7700/8100 LDOS voltages.

 

[yair37]

There is just 1 LDO on U8100, PP1V8_S2SW_CLVR_VDDC1_LDO - 0v
"all" the rest LDO'S on the board:
PP3V3_UPC1/2_LDO 3.3v
PPVDD_LDO_NAND0_OCARINA 1.5v
PP5V_S2_HDMI_LDO 5v
P5VS2TPS_PWR_EN_R_LDO 1.9v
PP1V5_P1V8VDDH_LDO15 0v no short.

 

[yair37]

the orange light on the charger ON then OFF for 2-3sec then ON and stay stable...

 

[2informaticos]

You have various LDOs on U8100; VLDO1/2/4/5/1V8/1V2.
Should be good to check there VCORE too.

Each VLDO has its corresponding VIN_LDO; check them also.

 

[yair37]

in the middle of the checking i was notice that the CPU is getting hot...i was disconnect put the fan and the fan start to work, i was said wired but look like is working...i was but the board in the body but then again is dead...put it out again but still dead, so maybe i was touch at something when i was checking the LDO voltage...

 

[yair37]

VLDO1 (PP3V3_S2) 0.2v VIN_LDO1(PP3V8_AON_MPMU) 3.8V
VLDO2 ( PP1V8_S2SW_CLVR_VDDC1_LDO) 0v VIN_LDO2 (PP3V8_AON_MPMU) 3.8V
VLDO3 (NC)
VLDO4 (PP3V3_AON) 3.3v VIN_LDO4 (PP3V8_AON_MPMU) 3.8V
VLDO5 (PP0V8_S2_CLVR_VDDDIG) 0.8v VIN_LDO5 (PP1V2_S2) 1.2V
VLDO6 (NC)
VLDO1V8 (PP1V8_AON) 1.8V VIN_LDO1V8 (PP3V8_AON_MPMU) 3.8V
VLDO1V2 (PP1V2_AON) 1.2V VIN_LDO1V2 (PP3V8_AON_MPMU) 3.8V
VCORE (PP1V5_AON_VCORE_MPMU) 1.5V VIN_VCORE (PP3V8_AON_MPMU) 3.8V

 

[yair37]

im sorry that its look messy but i was make big space between but it didnt do it..

 

[yair37]

VLDO2 ( PP1V8_S2SW_CLVR_VDDC1_LDO)1.8v sorry my mistake.. look like all voltage are o.k

 

[yair37]

also PP3V3_S2 3.3v
all the voltage pulsing with the charger..

 

[2informaticos]

Do you mean ALL voltages, including PPBUS_AON and 3V8_AON, or just LDOs pulsing?

 

[yair37]

PPBUS_AON and 3V8_AON also pulsing every 2-3 sec

 

[2informaticos]

Check them with battery connected too.

 

[yair37]

with battery connection the charger light still pulsing but PPBUS_AON and 3V8_AON voltage are stable 12.1v and 3.8v

 

[2informaticos]

The before mentioned LDOs are stable too?
Any chance to enter DFU?

 

[yair37]

o.k i was put the board back and try to put it in DFU the apple logo show for 1-2sec and off.. i was try to put it in recovery mode its say that it preparing to enter but when it need to enter its shot off.
sometimes im getting the "!" sign with support.apple.com/mac/restore
i was able one time to enter to DFU but i was get "error 2006" an i didnt able to enter DFU again.
there is no usb activity..

 

[2informaticos]

Did you try DFU with both Magsafe 3 and battery connected?

 

[yair37]

Yea and the charger still with orange light pulsing..

 

[2informaticos]

May have problems with M1, or SSD.

But there should still be something wrong on the USB-C area of the port with strange behavior.
Compare diode mode readings on more components; between different ports.