SOLVED: A1466 820-00165 - Missing PP5V_S5 and PM_SLP_S5_L

[it-solve]

Not turning on, managed to turn it on after cleaned little bit of oxidation around SMC and with SMC bypass. Worked for a bot and stopped turning on.

No current draw

PPVRTC_G3H = 3.41V
PP5V_S5 = 0V
PM_SLP_S5_L = 0V

No visible short or damaged traces/components

 

[2informaticos]

Post SMC_RESET_L, SMC_PM_G2_EN, AVREF_SMC and exact PPBUS_G3H voltage.

 

[it-solve]

SMC_RESET_L = 0V
SMC_PM_G2_EN = 0V
AVREF_SMC = 3.298V
PPBUS_G3H = 8.177V

 

[2informaticos]

"SMC_RESET_L = 0V"
Fix that first!

Check U5110 voltages.
Be sure J6100 is not corroded.

 

[it-solve]

Not sure why but now I get SMC_RESET_L = 3.39V, but it ws still 0A power draw.

I went and touched up the resistors around the SMC as they had some minor oxidation appearance.

Now I get 0.18A, no fan spin. It takes a while until it starts pulling any current.
I get around 45*C / 30*C areas on these two components



U7320- I replaced but still does the same hot spot
U3900 - Top right corner around PIN1 is warming up too

 

[2informaticos]

Did you reball SMC?
Should do it...

 

[it-solve]

reballed and replaced the SMC, was clean underneath. 0.18A and same heat pattern as the IR screenshot

 

[2informaticos]

What is actual PPBUS_G3H voltage?
Do you get amber light on Magsafe?

Check SMC_LID if stays high.

 

[it-solve]

PPBUS_G3H = 8.58V
SMC_LID = 3.39V

yes orange light

U7320 gets very hot

 

[2informaticos]

Check Q7320/1 and R/C7321.
Be sure to have good solders at U7320.

 

[it-solve]

Found it, thanks @2informaticos. Seems bridge was shorting the line.

Although no corroded pad or heavy liquid signs, SMC replacement resolved the initial issue.