MacBook 12" 2016 820-00244

[waterchill]

Good day friends, so I have here this MacBook which is drawing 20V 180mA only the Mainboard and 400mA with battery. No Apple logo no boot. I have actually no clue where start to check voltages because it is drawing current. Could it be that is a cpu damage like the 2015 models?

greets

[mon2]

Re: MacBook 12" 2016 820-00244

Check voltage to ground of PPBUS_G3H @ F7040.

Also confirm the voltage to ground of PP3V3_G3H.

[waterchill]

Re: MacBook 12" 2016 820-00244

Thanks for help

Here are some voltages:

PPBUS_G3H = 8,70V
PP3V3_G3H = 3,30V
PPDCIN_G3H = 19,7V
PP3V3R3V0_AON = 3,3V
PP5V_G3H = 5,1V
PP5V_S4 = 5,1V
PP5V_S0 = 5,1
PP3V3_S5 = 3,3V
PP3V3_SUS = 3,3 V
PP3V3_S4 = 3,3 V
PP3V3_S0 = 3,3V
PP1V8_SUS = 1,8V
PP1V8_S3 = 1,8V
PP1V5_S0 = 1,5V

[mon2]

Re: MacBook 12" 2016 820-00244

Attach a USB mouse. Do you see activity on the mouse during boot? (Red led)

[waterchill]

Re: MacBook 12" 2016 820-00244

Not sure how to do this because there is only one usb port. I have USB hub which has 2 normal usb ports and usb-c for load but if you plug in the mouse and plug in DC there is mouse activity without macbook.

[mon2]

Re: MacBook 12" 2016 820-00244

Use your external USB hub with any USB thumb drive with a led and connect all to your laptop.

Check if the led on the thumb drive flickers during power on cycle. Checking for USB activity which is linked to the USB host controller inside the PCH (CPU).

[waterchill]

Re: MacBook 12" 2016 820-00244

It looks like it would like to read something and then it cut down the power. I see a problem because with the hub it is only providing 5V not 20V. Actually I have plugged in power for little longer and it seems to charging the battery actually with 1,4A and 20V. I will wait untli fully charged and try later to start with battery. I have noticed that the D6900 light is on. I don't know what this is for. With the hub the Diode is blinking.

[mon2]

Re: MacBook 12" 2016 820-00244

If the USB drive LED is blinking then there is hope that the CPU is alive. Yes, do continue to review with a pre-charged battery.

A good USB hub for Type C should permit the negotiations to 20V power delivery contract.

Be sure you are using the original or confirmed suitable Type C power adapter that can deliver 20V.

[waterchill]

Re: MacBook 12" 2016 820-00244

So the charging looks like fake charging because since one hour still 1,4amps. The whole mainboard is warm especially the cpu. I can also plug off the charger, system still running with battery because if connect usb stick the led on the stick is on. Also the monitor notice that there is a signal but no signal there.Very strange

[mon2]

Re: MacBook 12" 2016 820-00244

Does the USB stick remain solid ON or also blinks?

If solid on, this means that the USB VBUS of 5v is present. If it blinks, then there are attempts being made by the CPU to read the contents of the USB stick.

This model is nasty for CPU failures.

[waterchill]

Re: MacBook 12" 2016 820-00244

I found an old usb stick, this turns on for 5 seconds and then goes off. Doesn't matter if macbook started with battery and only plugged in usb stick or with usb hub

[mon2]

Re: MacBook 12" 2016 820-00244

Check the voltage to ground of

PPVCORE_S0_CPU


Remove all power. Meter in resistance mode.

Check the resistance to ground of PPVCORE_S0_CPU.

Post your measurements.

[waterchill]

Re: MacBook 12" 2016 820-00244

Voltage is 0,0V and Resistance 10,2ohm. Measurements took on C1130

[waterchill]

Re: MacBook 12" 2016 820-00244

I have checked with a 2017er 12" macbook, resistance is same 10,5ohm but voltage is 0,635V. I will later check the parts which producing this voltage

[mon2]

Re: MacBook 12" 2016 820-00244

PPVCORE_S0_CPU regulator will have an enable pin. Check the voltage to ground of the enable pin to confirm if the power rail is being enabled or not.

[waterchill]

Re: MacBook 12" 2016 820-00244

I have checked:

VCIN of U7210 and U7230 = 5,10V
VIN of U7210 and U7230 = 8,70V

ZCD_EN = 0V = CPUCORE_FCCM

CPUCORE_FCCM is produced by U7100

VIN of U7100 = 8,7V
VCC of U7100 = 5,1V

I don't see an enable pin for U7100. Schematics says for VIN 12,9V I got 8,7V. Maybe this is problem or bad U7100? Or something else?