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*SOLVED* 820-00923, does not power on, PM_SLP_S5_l is missing

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donnos

Member
hello, i a MBP touchbar A1706 not turning on
No liquid damage of any kind. or any shorts

20V on charger
PPBUS 13V
PP5V_S5 5V
PP3v3_s5 3.3V
PM_SLP_SUS_L 3.3V
SMC_ADAPTER_EN 3.3V
PM_BATLOW_L is 0V
32MHZ and 24MHZ present (verified with Oscope)
PM_PWRBTN_L reacts if you trigger SMC_ONOFF_L, before trigger 3.3V, during trigger 0.34V release trigger 3.3V.

not sure where to move on from here
 
2informaticos

2informaticos

Administrator
Staff member
First of all, welcome to the forum!

PM_BATLOW_L must be high; if not, PCH will not start power on sequence.
Try to start in SMC bypass mode.
Also try with both charger and battery connected.
 
Last edited:
D

donnos

Member
With Battery connected, it seems to be charging the battery. getting 300-700mA on charger

PM_BATLOW_L is 0 no matter battery is connected or not.
and not sure how to do SMC bypass though, tried on another A1708(working fine laptop but once i press and hold the power button it just boots up normally)
  • Disconnect the power adapter
  • Hold the power button for 10 seconds
  • While holding the power button reconnect the power adapter
  • Continue to hold the power button for another 10 seconds
Did this on the dead laptop

with battery connected, on meter reads 20v 300mA for about 3 seconds and drops to 20v 30mA
without battery connected, on meter its reads 5v 40mA when i hold on the power button, goes up to 20V 30mA when i release the power button
 
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donnos

Member
RTC_RESET_L is 3v
PCH_SRTCRST_L 3v
both 32MHZ and 24MHZ present
pp1v0_sus 1V
so far this is the only RTH signals listed in the schematic. have i missed any?
 
2informaticos

2informaticos

Administrator
Staff member
RTC signals are not clearly delimited in the new schematics.
However, PCH_INTRUDER_L is still mandatory.

Check if R1451 is good.

BTW, I doubt you get 32MHz in any point.
 
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donnos

Member
PCH_INTRUDER_L is 2.85V
R1451 is good @10K ohm

*new findings*
i'm measuring 5ohm to ground on PM_BATLOW_L side. Tried injecting 1V into it, for split second, meter went up and went back to zero. i measure again, its now 70+ohm.
Now PM_BATLOW_L reads 0.24V
i check UB0000 and U2800, i see a big crack on UB000. i guess this is the cause then.
 
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