820-01521 only shows 5V 0.04A

**kingskie** · 04-19-2022, 10:40 PM

Hello,

i've been working on macbook air 820-01521
it is dead no charging. tried to connect to apple configurator always shows accessories not supported.

using amp meter only shows 5V and 0.04A

here are some measurements:

PPBUS_G3H = 12.26V
PP3V3_G3H = 3.275V
PP5V_G3S = 0V
PP20V_USBC_XA_VBUS = 5V (can i inject 20V 1A here?)

**reassor** · 04-20-2022, 03:11 AM

First check why there is no 20v.
Check CD chips.
Most of the time if you manage to make them go board will wake up.

Do not start from back

PP5VG3S_EN present?

How do you have 12.2v on main rail?
Do you meassure with battery connected? (come on)

**mon2** · 04-20-2022, 09:03 AM

Quote:

PP20V_USBC_XA_VBUS = 5V (can i inject 20V 1A here?)

No!! If you are not getting to 20v, something is wrong.

Remove all power. Meter in diode mode.

Red lead - yes RED meter lead to ground.

Black meter lead to a LDO rail of each ACE power delivery controller.

Check the LDO rails in diode mode of each ACE controller and post the readings.

Repeat for each ACE device.

**kingskie** · 04-22-2022, 09:54 PM

Quote:

Originally Posted by reassor

First check why there is no 20v.
Check CD chips.
Most of the time if you manage to make them go board will wake up.

Do not start from back

PP5VG3S_EN present?

How do you have 12.2v on main rail?
Do you meassure with battery connected? (come on)

there is no rail called PP5VG3S_EN

yes i have 12.26V on PPBUS rail

**kingskie** · 04-22-2022, 10:00 PM

Quote:

Originally Posted by mon2

No!! If you are not getting to 20v, something is wrong.

Remove all power. Meter in diode mode.

Red lead - yes RED meter lead to ground.

Black meter lead to a LDO rail of each ACE power delivery controller.

Check the LDO rails in diode mode of each ACE controller and post the readings.

Repeat for each ACE device.

PP3V3_UPC_XA_LDO = 26K ohm
PP3V3_UPC_XB_LDO = 25K ohm
PP5V_S5_LDO = 15.4K ohm

**mon2** · 04-23-2022, 06:55 AM

These are resistance readings. Do you have a diode scale on your meter? Can you post a pic of your meter?

Then review my earlier post on how to use the diode mode scale and take the measurements.

**kingskie** · 04-24-2022, 11:15 PM

Quote:

Originally Posted by mon2

These are resistance readings. Do you have a diode scale on your meter? Can you post a pic of your meter?

Then review my earlier post on how to use the diode mode scale and take the measurements.

i'm using fluke 101

**inflex** · 04-25-2022, 06:34 AM

Quote:

Originally Posted by kingskie

i'm using fluke 101

Press the yellow button to cycle through to diode-mode.

It'll likely show a diode symbol on the screen

**Simplebeans** · 04-25-2022, 03:37 PM

As mon2 said kingskie, checking diode mode readings should start to give you a idea of which ACE controller may be acting differently. It may show all the same readings for all but it is a good place to start to see any differences.

**kingskie** · 04-26-2022, 03:49 AM

Quote:

Originally Posted by inflex

Press the yellow button to cycle through to diode-mode.

It'll likely show a diode symbol on the screen

U3200
PP3V3_G3H_RTC = 0.425
PP3V3_UPC_XB_LDO = 0.466
PP1V8_UPC_LDOA = 0.482
UPC_XB_R_OSC = 0.481
UPC_XA_UART_TX = 0.682
PP1V1_UPC_XB_LDO_BMC = 0.460
UPC_XB_GPIO1 = 0.705
PP1V8_SLPS2R = 0.327
PP1V8_UPC_XB_LDOD = 0.444
UPC_XB_SPI_CS_L = 0.536
UPC_XB_SPI_CLK = 0.519
UPC_XB_SPI_MOSI = 0.541
UPC_XB_SPI_MISO = 0.537
I2C_UPC_XB_DBG_CTL_SCL = 0.716
I2C_UPC_XB_DBG_CTL_SDA = 0.715
PHV_INT_XB_G3H = 0.589
UPC_XB_GATE2 = 0.595
PPDCIN_G3H = 0.519
PP5V_G3S = 0.393
TBT_POC_RESET = 0.514
USB_X_RESET_L = 0.707
TBT_X_USB_PWR_EN = 0.492
PP20V_USBC_XB_VBUS = 0.108
USBC_XB_CC2 = 0.550
USBC_XB_CC2 = 0.533
USBC_XB_SBU2 = 0L
PD_TBT_XB_LSRX = 0.692
PD_TBT_XB_LSTX = 0.759
USB_UPOC_XB_F_P = 0.580

U3100
PP1V8_UPC_XA_LDOD = 0.448
PP1V1_UPC_XA_LDO_BMC = 0.461
PP3V3_UPC_XA_LDO = 0.468
PP1V8_UPC_XA_LDOA = 0.482

The lowest is PP20V_USBC_XB_VBUS and USBC_XB_SBU2 is 0L

**mon2** · 04-26-2022, 05:15 AM

Do you see the same voltage and current draw for each USB type C port?

What are the voltage readings of the following?

PP1V8_SLPS2R

PP1V1_SLPS2R

**kingskie** · 04-26-2022, 11:13 PM

Quote:

Originally Posted by mon2

do you see the same voltage and current draw for each usb type c port?

What are the voltage readings of the following?

pp1v8_slps2r

pp1v1_slps2r

pp1v8_slps2r = 1.793v
pp1v1_slps2r = 1.096v

**mon2** · 04-27-2022, 05:08 AM

These 2 rails are ok. They power the T2 device.

Do you see the same voltage and current draw for each USB type C port?

**kingskie** · 04-27-2022, 09:27 PM

Quote:

Originally Posted by mon2

These 2 rails are ok. They power the T2 device.

Do you see the same voltage and current draw for each USB type C port?

yes they both have the same current draw...could it be T2 chip is the culprit or PMIC?

**kingskie** · 05-09-2022, 04:36 AM

any suggestions?

**mon2** · 05-09-2022, 04:59 AM

SBC_XB_SBU2 = 0L

Is not correct for this diode reading. Can you check again?

It should be about 0.65.

Check also

USBC_XB_SBU1

USBC_XA_SBU1
USBC_XA_SBU2

**kingskie** · 05-09-2022, 10:21 PM

Quote:

Originally Posted by mon2

SBC_XB_SBU2 = 0L

Is not correct for this diode reading. Can you check again?

It should be about 0.65.

Check also

USBC_XB_SBU1

USBC_XA_SBU1
USBC_XA_SBU2

i checked USBC_XB_SBU2 from the test point that i attached still OL
USBC_XB_SBU1 = OL
USBC_XA_SBU1 = OL
USBC_XA_SBU2 = OL

**mon2** · 05-10-2022, 02:54 AM

Post a pic of your multimeter so we can confirm the diode mode setting.

**kingskie** · 05-10-2022, 03:00 AM

Quote:

Originally Posted by mon2

Post a pic of your multimeter so we can confirm the diode mode setting.

this is my multimeter

**mon2** · 05-10-2022, 03:52 AM

You are in ohms mode.

Press the yellow button till you see the diode symbol and measure again.

04-19-2022, 10:40 PM	#1
kingskie Senior Member Join Date: Oct 2014 City & State: tangerang My Country: indonesia I'm a: Knowledge Seeker Posts: 145	820-01521 only shows 5V 0.04A Hello, i've been working on macbook air 820-01521 it is dead no charging. tried to connect to apple configurator always shows accessories not supported. using amp meter only shows 5V and 0.04A here are some measurements: PPBUS_G3H = 12.26V PP3V3_G3H = 3.275V PP5V_G3S = 0V PP20V_USBC_XA_VBUS = 5V (can i inject 20V 1A here?)

04-20-2022, 03:11 AM	#2
reassor Senior Member Join Date: Apr 2021 City & State: Tychy My Country: Poland I'm a: Knowledge Seeker Posts: 107	Re: 820-01521 only shows 5V 0.04A First check why there is no 20v. Check CD chips. Most of the time if you manage to make them go board will wake up. Do not start from back PP5VG3S_EN present? How do you have 12.2v on main rail? Do you meassure with battery connected? (come on) Last edited by reassor; 04-20-2022 at 03:15 AM..

04-23-2022, 06:55 AM	#6
mon2 Badcaps Veteran Join Date: Dec 2019 City & State: Windsor, Ontario My Country: Canada Line Voltage: 110VAC I'm a: Knowledge Seeker Posts: 4,052	Re: 820-01521 only shows 5V 0.04A These are resistance readings. Do you have a diode scale on your meter? Can you post a pic of your meter? Then review my earlier post on how to use the diode mode scale and take the measurements.

04-25-2022, 03:37 PM	#9
Simplebeans Senior Member Join Date: Sep 2021 City & State: Leicester My Country: UK I'm a: Knowledge Seeker Posts: 126	Re: 820-01521 only shows 5V 0.04A As mon2 said kingskie, checking diode mode readings should start to give you a idea of which ACE controller may be acting differently. It may show all the same readings for all but it is a good place to start to see any differences. Last edited by Simplebeans; 04-25-2022 at 03:45 PM..

04-26-2022, 05:15 AM	#11
mon2 Badcaps Veteran Join Date: Dec 2019 City & State: Windsor, Ontario My Country: Canada Line Voltage: 110VAC I'm a: Knowledge Seeker Posts: 4,052	Re: 820-01521 only shows 5V 0.04A Do you see the same voltage and current draw for each USB type C port? What are the voltage readings of the following? PP1V8_SLPS2R PP1V1_SLPS2R

04-27-2022, 05:08 AM	#13
mon2 Badcaps Veteran Join Date: Dec 2019 City & State: Windsor, Ontario My Country: Canada Line Voltage: 110VAC I'm a: Knowledge Seeker Posts: 4,052	Re: 820-01521 only shows 5V 0.04A These 2 rails are ok. They power the T2 device. Do you see the same voltage and current draw for each USB type C port?

05-09-2022, 04:36 AM	#15
kingskie Senior Member Join Date: Oct 2014 City & State: tangerang My Country: indonesia I'm a: Knowledge Seeker Posts: 145	Re: 820-01521 only shows 5V 0.04A any suggestions?

05-09-2022, 04:59 AM	#16
mon2 Badcaps Veteran Join Date: Dec 2019 City & State: Windsor, Ontario My Country: Canada Line Voltage: 110VAC I'm a: Knowledge Seeker Posts: 4,052	Re: 820-01521 only shows 5V 0.04A SBC_XB_SBU2 = 0L Is not correct for this diode reading. Can you check again? It should be about 0.65. Check also USBC_XB_SBU1 USBC_XA_SBU1 USBC_XA_SBU2

05-10-2022, 02:54 AM	#18
mon2 Badcaps Veteran Join Date: Dec 2019 City & State: Windsor, Ontario My Country: Canada Line Voltage: 110VAC I'm a: Knowledge Seeker Posts: 4,052	Re: 820-01521 only shows 5V 0.04A Post a pic of your multimeter so we can confirm the diode mode setting.

05-10-2022, 03:52 AM	#20
mon2 Badcaps Veteran Join Date: Dec 2019 City & State: Windsor, Ontario My Country: Canada Line Voltage: 110VAC I'm a: Knowledge Seeker Posts: 4,052	Re: 820-01521 only shows 5V 0.04A You are in ohms mode. Press the yellow button till you see the diode symbol and measure again.

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