820-3435 PM_SLP_S4_L and PP5V_S4RS3 Pulsing

[No-Clean]

Clean board, old but clean

PPBUS: 8.58V
3V42: 3.4V
VRTC_G3H: 3.3V
5V_S5: 5V
3V3_S5: 3.3V
3V3_S5: 3.3V

Checked all coils for shorts and nothing

 

[2informaticos]

Check for pulse on all coils.
Also check U1950 pins 7 & 3.

PLT_RESET_L pulsing too?
Just in case, test SMC bypass...

 

[No-Clean]

Missing L3095,
Pulsing L7520, L7130, L7630, L7430
Steady L7560

U1950 Pins 7 & 3 pulsing.
PLT_RESET_L 0V
SMC bypass same thing

 

[2informaticos]

So no pulse at CPU core coils for sure?
What is diode mode reading there?
Compare with good board.

CPU_VR_EN pulsing?
Also check CPU_VR_READY.

 

[No-Clean]

Sorry about that L7630, L7430, L7310 and L7320 are also pulsing, I don't know why I did not see that in the first place.

CPU_VR_EN and CPU_VR_READY also pulses about every 4 seconds.

 

[2informaticos]

CPU_VCCST_PWRGD pulsing too?
If yes, check for pulse all PCH's rails from page 11.
May have a broken coil, or resistor.

 

[No-Clean]

Checked the resistors on page 11 as well as coils and caps, all are fine.

Put board on oven for 15 minutes and now it is working, maybe PCH is dying, lets see.

Thanks!

 

[2informaticos]

Very likely accumulated crap underneath PCH.
heating with quality flux, was the next step in the process.