macbook air a1932 820-01521, no power

madjid

New member
Hi, i have a macbook air a1932 820-01521, no power, restor t2 ok no problem but no display or boot on the macbook, no liquid damage, very clean, no short, I changed U7000 and always the same result: PPBUS_G3H 12V66 stable but low and CHGR_BGATE not stable 12V66 at 0V20, I removed F7000 and F8400 to measure but same result.
Do you have an idea please ? Thanks

measures
PP3V3_G3H 3V3
PPBUS_HS_CPU 12V66
PP3V3_G3H_RTC 3V3
PP3V3_G3H 3V3
PPDCIN_G3H 20V4
PP5V_G3S 5V
PP5V_S5_LDO 5V
PPVIN_G3H_P5VG3S 12V66
PP3V3_G3S 3V3
PP3V3_G3SSW_SNS 0V
PP1V8_G3S 1V8
PPVCC_S0_CPU 0V
PPVCCSA_S0_CPU 0V
pp1V8_SLPS2R 1V8
CHGR_BGATE 12V3and0V20 the voltage oscillates
PPVBAT_G3H 12V3and0V20 the voltage oscillates

trackpad click, no sound, no display, but restore t2 ok
charger plugged in 20v2 and 1a07

ps: sorry for my english i translate by google, i am french
 

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2informaticos

Administrator
Staff member
First of all, welcome to the forum!

"PPBUS_G3H 12V66 stable but low"
Low what?
Voltage is correct!

This board should boot without battery connected.
However, fan will spin to max and system gets very slow.
You need first to get correct voltages for the big coils.

"I removed F7000 and F8400"
Why?
These coils are not related in any way.
F7000 is for battery, not for PPBUS_G3H!

Test the board alone on the desk; nothing connected, apart of charger.
Check if you get voltage on big coils; like L8100/02, L7290...
 

madjid

New member
Thanks for your answer, I thought PPBUS_G3H must be at 13v01 for that I say mine is low 12.66, so I thought there was a leak that's why I removed f7000 and f8400 for take the PPBUS_G3H measurement but still at 12v66, if you tell me it's normal then ok. I put back f7000 f8400.

coil measure :
L8100 0V47
L8102 0V
L7290 0V
L7230 0V
L7210 L7430 L7410 = 0V
L7030 6V7
L7690 3V3
L7670 5V12
L9060 0V
L8410 0V
 

2informaticos

Administrator
Staff member
Check diode mode to ground on the big coils.
Switch to ohm scale for CPU ones; as usual for less than 010 readings on diode mode.
 

madjid

New member
L8100 0V47 97 ohms
L8102 0V 118 ohms
L7290 0V 33,3 ohms
L7230 0V 17,1 ohms
L7210 PPVCORE 18 ohms
L7430 14,7 ohms
L7410 0V 14,7 ohms
L7030 6V7 8,34 Mohms
L7690 3V3 13 Mohms
L7670 5V12 0,538 Kohms
L9060 0V 14,5 Koms
L8410 0V 120Koms
 

2informaticos

Administrator
Staff member
I said to use ohm scale ONLY for very low readings in diode mode.
K/Mohm readings are not so useful as you think.
And I hope you will correctly check in diode mode (red probe on ground).

Post U8100 voltages.
 

madjid

New member
Yes sorry, mode diode :

L8100 92 ohms
L8102 112 ohms
L7290 157 ohms
L7230 24 ohms
L7210 24 ohms
L7430 L7410 20 ohms
L7030 434 ohms
L7690 345 ohms
L7670 330 ohms
L9060 260 ohms
L8410 669 ohms

PP1V2_S3 = 0V45
R8103 PP5V_G3S_P1V1REG = 5v
P1V2REG_VREF = 0V
PPBUS_HS_CPU 12V66
 
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2informaticos

Administrator
Staff member
Why do you write "ohms", if is diode mode???
BTW, do not write "V" instead.

I was expecting to see voltage reading for pins 16 & 17 of U8100...
 

madjid

New member
if you prefer
measure Diode :
L8100 92
L8102 112
L7290 157
L7230 24
L7210 24
L7430 L7410 20
L7030 434
L7690 345
L7670 330
L9060 260
L8410 669

resistance measurement :
L8100 0V47 97 ohms
L8102 0V 118 ohms
L7290 0V 33,3 ohms
L7230 0V 17,1 ohms
L7210 PPVCORE 18 ohms
L7430 14,7 ohms
L7410 0V 14,7 ohms
L7030 6V7 8,34 Mohms
L7690 3V3 13 Mohms
L7670 5V12 0,538 Kohms
L9060 0V 14,5 Koms
L8410 0V 120Koms

Pin 16 PVDDQ_EN_R 0v
Pin 17 PD_P1V2_S3_EN 0v21

I still have a lot to learn sorry

I looked at PP1V2_S3 = 0V45, Switch U8240 is not powered by PP3V3_S5 0v
 
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2informaticos

Administrator
Staff member
You cannot expect 1V2_S3, if U8100 doesn't even get enable signal.
0.45V made me think something might be wrong with the chip itself; seems not.

Check if PCH_RTC_RESET_L is present.
Also trigger PMU_ONOFF_L (SWE010) and check for drop pulse at PCH_PWRBTN_L (at same time).
 

madjid

New member
PCH_RTC_RESET_L 3v
PMU_ONOFF_L 3v28
PCH_PWRBTN_L 3v3 for two seconds when GND et PMU_ONOFF_L are connected
 

2informaticos

Administrator
Staff member
"PCH_PWRBTN_L 3v3 for two seconds when GND et PMU_ONOFF_L are connected"
You should note 3V-0V-3V when trigger PMU_ONOFF_L; must stay at 3V in the rest of time.
 

madjid

New member
it's very difficult to get it, but when I get there it goes from 3v3 to 0v without going back to 3v3

sometimes I get 0v5 1v2 but it goes back to 0v and stays at 0v
 
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2informaticos

Administrator
Staff member
Once PMU_ONOFF_L is released, PCH_PWRBTN_L must go back to 3V.

To make your job easy, solder an wire on a convenient point of PMU_ONOFF_L line; like pin 2 of SWE001.
Then touch any metal plate, to simulate power button.
 

madjid

New member
yes I tried many times, always the same the 3v comes but leaves too early and does not come back once SWE001 is released
 
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