820-00045 no boot, no activity

raainxx

Member
Hi,
i try to solve my first macbook, when i plug the original power adapter 87W, i have nothing on the display.
I dissassemble the mac, the logic board is clean (no liquid). the customer say before this problem, the mac shutdown intermittent.
i measure this Voltage:
PPDCIN_G3H=20V
PPBUS_G3H=8,59V
no led on battery maybe is too low.
can you help me please?
 

raainxx

Member
I check all rails except PPVBUS_E85,PP5V1_S4SW_CC1,PP5V1_S4SW_CC2 i can't measure.
all rails are good except
PPVIN_G3H_P3V3G3H=20V
PP5V_S0SW_LCD=0V
PP5V1_S4SW=0v
PP1V05_S4SW=0V
i have only the power adapter without battery
 

dukefawks

Administrator
The 20V would indicate that the SMC is running and there is communication with the charger.

PP5V_S0SW_LCD=0V
PP5V1_S4SW=0v
PP1V05_S4SW=0V
What does this mean? They are 2 random lines and of course they are all 0V as none of the S4 rails are present. Were all rails checked for short to GND?
 

raainxx

Member
I don't undetand duke sorry
i already check the PPxxx with 0V is not short. I check each signal where voltage is generate but i find why the signal is 0V.
When you say S4 rail, it's all signal with S4 in the name? or other thing?
i try with motherboard only with connector usbc and power adapter, do i need more? when i put display, nothing on screen.
on apple service manual, i see use an power adapter 5W when i use the minimal config to boot. do you use 87W adapter?
is it normal all the board heat?
thanks
 

dukefawks

Administrator
This board will power just fine from any ORIGINAL Apple USB-C charger as it only requires the smallest one?

is it normal all the board heat? What does that mean?
 

raainxx

Member
No Title

i check the service manual guide (i have a friend who work for apple service center). you can look the minimal configuration talk about a 5W power adapter.
it's not very important, heat a 40°c (thermalgun), i think it's the CPU. normal?
PP5V_S0SW_LCD, PP5V1_S4SW,PP1V05_S4SW, this voltage are necessary to start the mac?
 

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dukefawks

Administrator
it's not very important, heat a 40°c (thermalgun), i think it's the CPU. normal?
PP5V_S0SW_LCD, PP5V1_S4SW,PP1V05_S4SW, this voltage are necessary to start the mac?

Huh? Is the CPU getting warm?
 
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