820-01598 No Boot

I have a 820-01598-A which won't turn on.

I can get it into DFU mode but can't successfully restore - USB Coms error

Getting the correct voltages for 0V9_SSD0 and 2V5_NAND_SSD0

PPBUS = 12.55v

Prior to attempting a DFU restore the fan repeatedly would spin for 1 second and then stop with a good 20-30s delay between. It does not anymore.

Can see from the casing/keyboard shield that there was liquid near U3100 but the board looks spotless.
 
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2informaticos

Administrator
Staff member
Check if all SLPS2R and AWAKE voltages are present.
Try revive option (not restore) in DFU mode.
If you are not sure about which macOS version is installed, try the second machine with Catalina, as Big Sur too.
 
To confirm that's,

PP0v8_SLPS2R
PP1v1_SLPS2R
PP1v8_SLPS2R

PP0v8_AWAKE
PP1v1_AWAKE
PP1v8_AWAKE

???

I have tried Revive, there was no error this time.

The machine no longer shows recovery in Configurator, it just says apple controller under the box which appears.

I can still get it into DFU

Does it make a difference if I am using configurator on a Big Sur or Catalina device? Have been using Catalina. No idea which OS the 820-01598 had installed.
 
Can that be done from Configurator?

How is it done?

Also I've yet to see anything on the screen of this MacBook. Would have thought after a revive I would get the Battery icon etc

Thanks!
 
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PP5V_G3H - 5.09v
PP3V3_G3H - 3.29v
PPVIN_S0SW_LCDBKLT - 0v
CHGR_LX2 - 12.92v
PPVCCEDRAM_S0_REG_R - 0v
PPVCCGT_CPU_PH1 - 0v
CPUGT_SW1 0v
CPUGT_SW2 - 0v
CPUCORE_SW1 - 0v
CPUCORE_SW2 - 0v
PPVCCSA_CPU_R - 0.1v
PP0V95_S0_CPUVCCIO_REG_R - 0.95v
PP1V2_S3_REG_R - 1.24v

Where voltage is present it is on both sides of the coil.
 
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So the short is coming after U7210

Im getting all voltage in

PPBUS_HS_CPU - 5v
PP5V_G3S_CPUREG_MISC - 5v

CPUCORE_FCCM - 2.5v
CPUCORE_PWM1 - 2.5v

Nothing on PPVCC_CPU_PH1.

Is it worth removing U7210 to see if the short goes or do you think the issue is further downstream or the processor.

The processor is warm but not hot.
 
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