820-00165-A green to orange no fan

[koby058]

Hi

Macbook air not power on. fan not auto starting

PM_RSMRST_L is 3.3v
PM_SLP_S5_L is low

Can you please help me diagnose?

Attached relevant part of logiwiki map

[mon2]

Re: 820-00165-A green to orange no fan

Hi Mr. Jaffa oranges

1) What is the voltage value to ground of PPBUS_G3H ?

2) What is the voltage value to ground of PP3V42_G3H ? Do you see the standard green / orange lights on the magsafe connector? If not, that needs to be fixed before proceeding further.

3) Assuming the above voltages are ok, review the attached shorting pads on the PCB. Using tweezers, short one of the pair of pads to mimic the ON/OFF button.

[koby058]

Re: 820-00165-A green to orange no fan

Hi mon2

Standart green to orange present.

PPBUS_G3H = 8.51
PP3V42_G3H = 3.4 (I think this multi meter is not the best)

I could not understand what pads should be shorted to ground from the attached

[mon2]

Re: 820-00165-A green to orange no fan

These are good voltages.

Apple / Foxconn / PCB designers apply SMD shorting pads onto the TOP and BOTTOM side of the PCB layout.

This is so you can remove the keyboard & trackpad and still turn on the logic board.

These pads for this logic board are @ R5115 & R5116.

Varying with how the logic board is on your table, you will find one pair only and these pads can be shorted with tweezers.

See attached.

[koby058]

Re: 820-00165-A green to orange no fan

Got it.

I have shorted them to ground but still Fan not powering on

just to mention I have 3.3v on pin one of R5115

What do you think?

[mon2]

Re: 820-00165-A green to orange no fan

Yes, that voltage is ok and is active LOW. So when you short with tweezers to GROUND, the logic board will turn ON. From memory, believe that you should have fan spin if all is well even without this shorting of the pads.

Review this excellent website that details the power up sequence of the same logic board:

https://www.it-tech.com.au/mac-q-a/pm-slp-s4-l-timing/

Continue to post your updates.

[koby058]

Re: 820-00165-A green to orange no fan

I have checked all voltages under this list in the link:

"If PM_SLP_S4_L missing, we need to check these before replacing the CPU/PCH."

and all are present, i don't have oscilloscope so did not tested SYSCLK_CLK32K_RTCX1 (RTCX1)

some times the macbook does start.

Maybe the PCH is done i don't know

[mon2]

Re: 820-00165-A green to orange no fan

When the board is NOT working, what is the voltage to ground of ALL_SYS_PWRGD ?

Are you testing with only the adapter is there also a battery connected?

Do go through the checklist from the above website - see attached.

[judamex]

Re: 820-00165-A green to orange no fan

Hi

Macbook air not power on. fan not auto starting

PM_RSMRST_L is 3.3v
PM_SLP_S5_L is low

Can you please help me diagnose?

Attached relevant part of logiwiki map

When the board is NOT working, what is the voltage to ground of ALL_SYS_PWRGD ?

Are you testing with only the adapter is there also a battery connected?

Do go through the checklist from the above website - see attached.

i have the same problem, and my measurement on ALL_SYS_PWRGD = 0V

[mon2]

Re: 820-00165-A green to orange no fan

From the same above website..

A valid ALL_SYS_PWRGD signal checks these power rails: PP1V8_S3, PP5V_S3, PP1V2_S3, PP1V05_S0, PP5V_S0, PP3V3_S0, PP1V5_S0. Any of these S3 or S0 state power rails malfunction will pull down the ALL_SYS_PWRGD signal and terminate the normal power-on process of Apple computers.

Check the voltage to ground of each of the above power rails.

[koby058]

Re: 820-00165-A green to orange no fan

When the board is NOT working, what is the voltage to ground of ALL_SYS_PWRGD ?

Are you testing with only the adapter is there also a battery connected?

Do go through the checklist from the above website - see attached.

ALL_SYS_PWRGD not present, testing with out battery. i did go through all this check list

[koby058]

Re: 820-00165-A green to orange no fan

From the same above website..



Check the voltage to ground of each of the above power rails.

None of them is present.

when i measure like, let say PP1V8_S3 the minute i plug the charger i see some voltage and immediately back to zero

[dellxps15]

Re: 820-00165-A green to orange no fan

post bios pin voltage, check if u have 5 volt s4 pulsing, post voltage of u1950

[judamex]

Re: 820-00165-A green to orange no fan

From the same above website..



Check the voltage to ground of each of the above power rails.

The Value of all are "0.0V" except "PP3V3_S0" is too low "0.06V"

[judamex]

Re: 820-00165-A green to orange no fan

post bios pin voltage, check if u have 5 volt s4 pulsing, post voltage of u1950

Voltage on U1950

1=0V
2=0.06v
3=0V
4=GND
5=0V
6=0V
7=0V
8=3.4V