820-3437 PP5V_S4RS3 pulses every 3-4 seconds

[No-Clean]

Board had corrosion on R6128 that got repaired fine.

M_BATLOW_L
M_DSW_PWRGD
CH_DSWVRMEN
M_RSMRST_L
M_PWRBTN_L
AND
P3V42_G3H
PBUS_G3H
PBUS_S5_HS_COMPUTING_ISNS
PBUS_S5_HS_OTHER_ISNS
PDCIN_G3H_ISOL
PVRTC_G3H] [p:C1910:1
P5V_S5
P3V3_S5
P3V3_SUS
ALL_SYS_PWRGD

All above rails are present and correct, PP5V_S4RS3 pulses every 3-4 seconds

Already reballed SMC and tried clean BIOS and checked pages 57-58 but no luck.

 

[2informaticos]

Please, take your time when post and write signal names correctly.
Forget copy/paste, if you cannot do it in decent mode.
Do you consider lost time to do that properly???

Remember, no need to measure same power rail in different points (PPBUS_x).

I'm wondering how do you get steady ALL_SYS_PWRGD when PP5V_S4RS3 is pulsing...

 

[No-Clean]

Will do, no problem.

ALL_SYS_PWRGD is 0V, I measured a different component.

Here is the list again:

PBUS_G3H Present
PVRTC_G3H Present
P5V_S5 Present
P3V3_S5 Present
P3V3_SUS Present
PP5V_S4RS3 pulses every 3-4 seconds
P5VS4RS3_EN_R pulses too
PM_SLP_S4_L pulses too
ALL_SYS_PWRGD Missing

 

[2informaticos]

"PBUS_G3H Present"
I hope is 12.5V and not 12.3V.

So no pulse at PM_SLP_S3_L and/or other big coils?

 

[No-Clean]

PBUS_G3H Present 8.59V this is a MBA

PM_SLP_S3_L pulses
L7430, L7630, L7310/20 VCORE all pulse

 

[2informaticos]

Check for pulse at pins 7 & 3 of U1950

 

[No-Clean]

Yes, both are pulsing.

 

[2informaticos]

Check ALL SPI Bus Series Termination resistors and their traces.
Be sure J6100 is clean; you may need to remove it.
Also try known good working BIOS.

 

[No-Clean]

No luck, no fix