820-00165 Random Power-On Issues

SairFecht

Member
History

Board came in no-power with minor corrosion on C1930 and R1931. Replaced both as part of the initial clean up pass. No other signs of any corrosion/junk anywhere else.

Symptoms

Board behaves, randomly, in different ways when power is applied.

1) Powers on drawing either 0.180, 0.200, or 0.250 amps, fan spins, fan goes off and it falls back to 0.025, then powers back on with original amperage. The readings below are from this state, as it's the most common occurrence. USB light, but no activity. No caps-lock activity. 80% of the time.
2) Powers on and sticks at 0.025. 20% of time.
3) This is the odd one -> Powers on and works completely normally, flashing folder mark, etc, but no backlight. Very rarely, but I've got it to do this twice.

Readings

PPBUS_G3H: 8.57
HS_COMP: 8.57
HS_OTHER: 8.58
PPDCIN_G3H: 18.15
PP3V42_G3H: 3.44
PPVRTC_G3H: 3.31
PP5V_S5: 5.1
PP5V_S4RS3: 5.1
PP5V_S0: 5.0
PP3V3_S5: 3.31
PP3V3_S4: 3.31
PP3V3_SUS: 3.31
PP3V3_S3: 3.31
PP3V3_S0: 3.31
PP3V3_S4SW_SNS: 3.31
PP1V8_S3: 1.79
PP1V2_S3: 1.2
PP1V05_SUS: 1.05
PP1V5_S0: 1.5
PP0V6_S0_DDRVTT: 0.6
PP1V05_S0: 1.05
PPVCC_S0_CPU: 1.7
PM_PCH_SYS_PWROK: 3.44
PLT_RESET_L: 3.3
RTC_RESET_L: 3.3
PCH_SRTCRST_L: 3.3
PCH_INTVRMEN: 3.2
PCH_DSWVRMEN: 3.2
PM_DSW_PWRGD: 3.4
PM_BATLOW_L: 3.3
PM_RSMSRT_L: 3.29
PM_PWRBTN_L: 3.4
PCH_INTRUDER_L: 3.0
 

2informaticos

Administrator
Staff member
Try original Magsafe 2 charger.
Also test the board alone, disconnecting LIO flex and other peripherals.
 

SairFecht

Member
The board is completely stripped from the machine, nothing attached. I?ve swapped for a known good IO board and flex, and I?ve tried it on a genuine charger.
 

2informaticos

Administrator
Staff member
Do NOT connect LIO flex untill get the board booting.
Use mouse connected to onboard USB port for control.
Check SMC_LID signal if stable.
Maybe need to reball SMC.
 
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