Macbook A1466 820-00165 25 AMps

[Instafixx]

PPBUS is 8.6V
Get MGasage
3v42 present
SMC_RESET_L present
PM_SLP_S4_L absent
U1950 voltages missing as well Pin 1 to 7.

Replaced U1950. Still the same

 

[2informaticos]

What about 3V3_S5/SUS?
Did you try SMC bypass?

 

[Instafixx]

3v3_S5/SUS present.
Tried SMC BYPASS.
No Fan Spin. Not Turning On.

 

[2informaticos]

PM_RSMRST_L goes high?
Trigger SMC_ONOFF_L and check for drop pulse at PM_PWRBTN_L.

 

[Instafixx]

PM_RSMRST_L goes high.
There is drop pulse when SMC_ONOFF_L is trigerred.

 

[2informaticos]

Check for pulse at PM_SLP_S4_L (at same time); it should stay high in fact.
If not, there is a problem with PCH...

 

[Instafixx]

PM_SLP_S4_L is absent since the beginning.

 

[2informaticos]

If doesn't react at same time with PM_PWRBTN_L, PCH is suspect.
Just in case, check its RTC signals.

 

[Instafixx]

It reacts. It goes up slightly when SMC_ONOFF_L is triggered.

 

[2informaticos]

Any reaction at PM_SLP_S3_L?
Also check for pulse at all coils.

 

[Instafixx]

So i just checked the board is pulsing every 5 seconds.
almost all big coils. Even PM_SLP_S4_L.
I replaced R1275. Still the same.

Current draw on the PSU is also the same.

 

[2informaticos]

Pins 7 & 3 of U1950 also pulsing?

Check diode mode and voltage pulse in page 58.

 

[Instafixx]

Yes both pulsing Pin 7 and 3 of U1950.
No shorts on any of the U8010-80.
Voltages are pulsing every 5 Seconds.

3v3_s5 Stable

 

[2informaticos]

Any history available?
Corrosion signs on the MLB?

Just in case, try to reflow PCH area, to eliminate eventually crap underneath.