MacBook Air a1466 820-00165-a doesn’t start

[kalilinux25]

Re: MacBook Air a1466 820-00165-a doesn't start

PPVRTC_G3H- 3.3v
RTC_RESET_L - 3.3v
PCH_SRTCRST_L - 3.3v
PCH_INTVRMEN_L- 3.3v
PCH_DSWVRMEN_L- 3.3v
SYSCLK_CLK32K_RTCX1 -0v
PP3V3_S5- 3.3v
PM_DSW_PWRGD- 3.4v
PP3V3_SUS- 3.3v
PM_BATLOW_L- 3.3v
PM_RSMRST_L- 3.3v
PM_PWRBTN_L- 3.4v

[kalilinux25]

Re: MacBook Air a1466 820-00165-a doesn't start

Post the voltage readings of U6100 SPI flash rom.

hi sir hope you can still help me

[jamesp]

NEED help with my a1466 macbook with mb 820-00165-a

problem is no voltage reading both pins of R7551 to send enable signal for pin 4 and will result to PP5V_S4RS3, measured L7520 indcutor for possible short to gnd but none have found. i watch yt videos of louiss rossman and he said before replacing U7501 we must check first PM_SLP_S4_L , and i did check but nothing i measured. is it correct to conclude that U0500 chip is the culprit? i checked also the PM_SLP_S4_L line and no short found. pls. help thanks

[mon2]

Review this flow chart:

https://logi.wiki/index.php/G3_to_S3..._and_Broadwell

[jamesp]

Review this flow chart:

https://logi.wiki/index.php/G3_to_S3..._and_Broadwell

yes thanks, i am at S4 stage where i can get no voltage reading that will enable the u7501 chip, and that PM_SLP_S4 comes from U0500 chip

[mon2]

Is PM_SLP_S4 pulsing or stuck at 0v?

What is the voltage to ground of PPBUS_G3H? Is it stable?

Do you have a stable PP3V42_G3H @ 3v42?

Be sure to use the original OEM power adapter suitable to power this logic board. This is important.

[jamesp]

Is PM_SLP_S4 pulsing or stuck at 0v?

What is the voltage to ground of PPBUS_G3H? Is it stable?

Do you have a stable PP3V42_G3H @ 3v42?

Be sure to use the original OEM power adapter suitable to power this logic board. This is important.

i am stuck at 0v on PM_SLP_S4_L , PPBUS_G3H is stable, i also have reading of 3.42 on OO3V42_G3H, And yes i am using oem pwr adapter

[mon2]

Confirm the PM_PWRBTN_L voltage when you press the power button. Test again when the power button is released.

Also review this video:

https://www.youtube.com/watch?v=GZz8WtEZBEU

[jamesp]

Confirm the PM_PWRBTN_L voltage when you press the power button. Test again when the power button is released.

Also review this video:

https://www.youtube.com/watch?v=GZz8WtEZBEU

PM_PWRBTN_L has a reading of 3v and pulled down as i press the pwr switch button on keyboard, when released it goes high again

[mon2]

What is the history of this unit? Any liquid damage? What is the exact voltage of PPBUS_G3H? This voltage will confirm if the SMC is working or not. If PPBUS_G3H is not the higher value, study the voltage to ground of the SCL / SDA lines on the battery which are shared by the battery pack, the SMC and the charger chip @ U7100.

[jamesp]

What is the history of this unit? Any liquid damage? What is the exact voltage of PPBUS_G3H? This voltage will confirm if the SMC is working or not. If PPBUS_G3H is not the higher value, study the voltage to ground of the SCL / SDA lines on the battery which are shared by the battery pack, the SMC and the charger chip @ U7100.

PPBUS_G3H reads 8.4vdc and both SCL AND SDA line on battery connector are logic high 3v , my friend who owns this laptop said there is accedental water spill on this long time ago but wait a week before trying to power up, and voila...problem occurs. through my scope theres no visible water damaged observed. i only stuck at the PM_SLP_S4_L signal. btw....letter L in signal name means Low?? if it does, maybe i should not expect a high logic value on this pin, am i wrong ? whats your idea on this? if this signal comes from CPU U0500, what other signal that triggers this cpu to give a logic high on this output PM_SLP_S4?

[mon2]

Review the steps 1-12 here for this signal:

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

[jamesp]

Review the steps 1-12 here for this signal:

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

wow, thank you very much for the link, its very informative, i might sleep now and do this tomorrow morning. its past midnight here in our place. i will share some update as quickly as i can. thanks again.

[jamesp]

here is an update....@Mon2 and others
i followed this link https://www.it-tech.com.au/pm-slp-s4-l-timing/
i have stopped at no.11 ...PM_RST_L is low , reading of 0v but pull-up resistor is ok at 100k and PP3V_SUS has 2.7 volts.
pls. see attached diagram with my readings
also checked for shorted to gnd on that signal PM_RST_L but ok not shorted. so probably i should jump to conclusion that it is the chip U8130 is the culprit as datasheet tells us that MR pin is high and threshold voltage is within the design....PIN 6 SHOULD have a high reading and not zero. can you guys confirm

[mon2]

Working on my beauty sleep but 3v3 rails are too low. Remove all power and measure the resistance to ground. Should not be at 2v7 unless a shorted part on the rail.

[jamesp]

Working on my beauty sleep but 3v3 rails are too low. Remove all power and measure the resistance to ground. Should not be at 2v7 unless a shorted part on the rail.

thats also i thought eventhough the chip has a minimum working voltage. the only correct voltage reading is PM_DSW_PWRGD which is i measured @ 3.42 v. all items in 11+1 checklist on the link that you gave me is 2.7v and the item no.6 i got a correct32khz clk. i will give another update, sorry o disturbed your sleep.

[jamesp]

Working on my beauty sleep but 3v3 rails are too low. Remove all power and measure the resistance to ground. Should not be at 2v7 unless a shorted part on the rail.

latest....found out PPDCIN_G3H_ISOL only has 15.5v but i can measure though a 3.42v on PP3V42. SAD i dont have other magsafe for verification. note that it is a original magsafe that i used. maybe this causes my 3.3v rail to have 2.7volt only of reading

[mon2]

Remove all power. What is the resistance to ground on C8130? This rail is being pulled down from the expected 3v3 value.

U8130 is looking for a threshold value of 3v or more before releasing the reset line else parked the output to be low.

[mon2]

From Rossmann forum..

15V on DCIN is fine and will not affect anything, schematic is lazy and states voltage for a 60W charger instead of 45W

[jamesp]

Remove all power. What is the resistance to ground on C8130? This rail is being pulled down from the expected 3v3 value.

U8130 is looking for a threshold value of 3v or more before releasing the reset line else parked the output to be low.

SORRY I have just read your reply just this time, good news, i have replaced U8130 with a part from donor board. confirmed that U8130 is pulling my PM_RSMRST_L down. now after replacement, the voltage of all that i mention with 2.7v reading still same, macbook now running.
L7560 = 2.8V
L7520 = 5.1 V PP5VRS3
PM_SLP_S4 = 2.8 V

USB port has power, camera is working, wifi is ok. battery is charging. sleep mode is ok.
i will update again if there is a problem that will manifest.

thanks mon2 for the link. that helps a lot, i almost threw my mac