[help]Macbook Air 820-3437 Dead

[phantom]

pp5v_s5 is not shorted.

 

[2informaticos]

Check diode mode to ground at pin 13 too.

 

[phantom]

0,011!! FUCK! how is it possible

 

[phantom]

ok now with another u7501 i have pp3v3_s5




0v on PM_DSW_PWRGD

SMC_S5_PWRGD_VIN 3,3v

S5_PWRGD not present

0v on PP3V3_SUS

0,3v on PM_PWRBTN_L

 

[phantom]

PM_PWRBTN_L is 0,3v but it should go to 0,3v when triggered!


r1405 is 1k, i have 3,3v on the other side...so i don't understand

SMC_ONOFF_L. 3,4v

SMC_RESET_L 3,2v

 

[2informaticos]

Do you have correct 3.3V at C7592?

 

[phantom]

yes

 

[2informaticos]

Try to isolate somehow pin 20/U7501.
It shouldn't pull down S5_PWRGD now; let discard that.

 

[phantom]

Just to understand: why do you think about u7501? I’ve seen that this line goes under smc also!

 

[2informaticos]

U7501 controls it; as already explained before.
Bad SMC can pulled it down, but is not usual.

Is more easy to isolate U7501, than SMC; on S5_PWRGD line.

 

[phantom]

What do you think: is it better to change u7501 with another one or isolate the pin?

 

[2informaticos]

Isolating the pin will give you an idea if the problem comes from U7501, or not.
There is still a chance to have bad SMC; however less probable.

 

[phantom]

tried another u7501, still the same

 

[phantom]

i will go crazy...i've soldered another smc..now i have 3,2 on the other side of r8141 but no power led on magsafe... i have even pwrbtn_l 3,4V!!!!!

ppbus_g3h is 8,16, PP3V3_S5_SMC_VDDA 3,4 sysonewire 3v (should be 3,4?!) PP1V2_S5_SMC_VDD 0,9 v!?!?!?!? should be 1,2? (line is not shorted)

 

[2informaticos]

Possibly bad solders under SMC; or bad chip...

 

[phantom]

i will resolder the old smc....i'm going crazy...with this smc i have S5_PWRGD...but smc doesn't work...

 

[phantom]

Problem is to find a donor board?

Could I take from 820-2796 ??

 

[2informaticos]

No way.
You can get it from 00165; probably from other MacBook Pro 2013 or newer.

In such case (not same donor model), will need to flash the correct firmware into SMC.
You can find SMCTools on Internet...

 

[phantom]

How to flash is macbook is dead ?

 

[2informaticos]

Your board doesn't work now.
If that is caused by bad SMC, you can flash it AFTER changed it; if is the culprit.