820-00165 PCH_INTRUDER_L 2.1V

[No-Clean]

I have a few boards from the past that all have the same problem:

PPBUS 8.6V
5V_S5 5V
3V3_S5 3.3V
PPVRTC_G3H 3.3V

But PCH_INTRUDER_L is around 2V and PCH_INTVRMEN is around 2.1V on ALL of them I have tried to force the signal with a 100K resistor, the voltage goes up to 2.9V (I am not sure if this is in range of a good signal) but after that the board still does not boot, what else should I check?

 

[2informaticos]

These signals come through high value resistor, which generate a voltage divider with multimeter's input impedance.
Your problem is not related.

Do you get 3V3_SUS?

 

[No-Clean]

Yes 3V3_SUS present at 3.3V

 

[2informaticos]

Trigger SMC_ONOFF_L and check for drop pulse at PM_PWRBTN_L.
If you catch it, check for pulse at PM_SLP_S4_L (at same time).

 

[No-Clean]

I do get a drop pulse on PM_PWRBTN_L

PM_SLP_S4_L is 0V when I trigger SMC_ONOFF I get a fast pulse that goes up towards 3... volts then drops down to 0V

 

[2informaticos]

Then check for pulse at PM_SLP_S3_L and all big coils too.

Test if board turns on in SMC bypass mode.

 

[No-Clean]

Ok discover that R7121/22 were blown, Im not sure if it was cause my LIO board was old and a little bit corroded, after replacing those resistors and testing with a different LIO board still same problem.

L7130 and L7560 are steady all other 0V, no pulse.

PM_SLP_S3_L 0V, pulses once when plugging charger then goes down to 0V and stays there.

SMC bypass same problem.

 

[2informaticos]

If both PM_SLP_S4/3_L pulse, you should catch pulses on all coils.
Check U1950 pins 7 & 3 for pulse.
Also check ALL_SYS_PWRGD if pulses.

 

[No-Clean]

PM_SLP_S3_L = 0V, pulses once when plugging charger then goes down to 0V and stays there so no pulsing here, just made the commend for reference.

U1950 pins 7 & 3 both 0V no pulse

ALL_SYS_PWRGD 0V no pulse

 

[2informaticos]

You must check at same time when pulsing PM_SLP_S4/3.
Trigger SMC_ONOFF_L and check for pulse on mentioned points and coils.

 

[No-Clean]

U1950 pins 7 & 3, PM_SLP_S3_L, ALL_SYS_PWRGD and big coils all get a pulse when I trigger SMC_ONOFF.

 

[2informaticos]

Any history available?
PLT_RESET_L pulsing too?
Check for pulse at all voltages from pages 11 & 58.

 

[No-Clean]

Board came in before but worked after a few measurements taken, now it is back again.

When I trigger SMC_ONOFF the board almost boots all the way and CPU seems to start to work, but shuts down shortly after.

PLT_RESET_L pulses to when I trigger SMC_ONOFF

 

[2informaticos]

May have accumulated crap underneath CPU/PCH.
You can try to heat using quality flux.
Maybe reballing SMC too...

 

[No-Clean]

Heating with good flux did not work, but booted once, that gave me hope so I did a complete reball of the CPU and now it is working constantly, thanks!