820-4924A magsafe orange no fan spin

[protocold]

Board looks clean, except there is some tiny corrosion around TP SPI_MSIO_R, no short there.

PP3V42_G3H = 3.42V

PP5V_S5 = 5v
PP3V3_S5 = 3.3v
AVREF_SMC = 3.3v

PP5V_S3/PP3V3_S3 not present.

triggered ONOFF (short pad R5115/16) and no pulse at PM_SLP_S4_L = 0V.

PCH_DSWVRMEN = 3.2v
PM_DSW_PWRGD = 3.4V
PM_BATLOW_L = 3.3V
PM_RSMRST_L = 3.3V

SMC bypass made no difference, board remain dead.

What now?

 

[2informaticos]

What about 3V3_SUS?

Check PCH's RTC (DC) signals.

 

[protocold]

3V3_SUS is present.

RTC_RESET_L = 3.3v
PCH_SRTCRST_L = 3.3v
PCH_INTRUDER_L = 3.052v
PCH_INTVRMEN = 3.23v

I just measure these voltages directly while it is powered, do i need to trigger anything while measuring these?

 

[2informaticos]

These signals must be present always.

Trigger SMC_ONOFF_L and check for drop pulse at PM_PWRBTN_L.
Be sure PM_RSMRST_L is kept always high.

 

[protocold]

PM_RSMRST_L is kept at high.

But trigger SMC_ONOFF_L cause NO drop at PM_PWRBTN_L. Always stuck at 3.4v

 

[2informaticos]

In this case SMC is the first suspect.

 

[protocold]

a stupid question... for some reason i cannot remove the SMC... I suspect perhaps due to glue on the 4 corner cannot be removed 100% under the chip...is there a trick?

 

[2informaticos]

It doesn't need too much heat to be removed from the corners.
And the small amount remained under the chip can't impede to remove the SMC.

Preheat the opposite board side first.
Removing CPU heatsink also helps.

 

[protocold]

This is 2015. Can i use the SMC from other years of A1502? e.g. 2013?

 

[2informaticos]

It should boot with other SMC.
Then you have to reflash it.

GitHub - MuertoGB/SMCTool: 💻 SMCTool is used to program LM4F SMC firmware on Mac devices made between 2013-2017 in EFI mode.

💻 SMCTool is used to program LM4F SMC firmware on Mac devices made between 2013-2017 in EFI mode. - MuertoGB/SMCTool

github.com