[HELP]a1990 820-01041 NOBOOT, STRANGE!

phantom

Member
Hi to all...820-01041 no liquid spill...3 usb ports stuck on 5v, the other port totally dead

Because of a small journey, I’ve ask a friend of mine, technician, to change the controller corresponding to the dead port

I don’t know why, I have changed all 4 controller

now i have 5v@0,269 on all 4 ports

According to this guide


I confirm that

i have all ldo's...

i have PPDCIN_G3H
i have TBA_VDDA (PPCHGR_VDDA)
i have PM_EN_P3V3_G3H (NC_CHGR_EN_VR1)
i have PP3V3_G3H

i can't find in schematic PP1V2_G3H_SMC_VDDC or PP1V2_S5_SMC_VDDC
i can't find in schematic PP3V0_G3H_AVREF_SMC or PP3V0_S5_AVREF_SMC
if it is PP3V0_G3H_RTC, i have 3,3v

i can't find SMC_RST, if it is TP_CHGR_SMC_RST_L, i have 1,7 and not 3v

if i connect the upper left or right port to my mac m1, i receive the message

"impossible to use accessory"

if i try to connect the others two ports, nothing happen

please help and sorry for my bad english!
 

2informaticos

Administrator
Staff member
Do you get 1V1 LDO BMC on the corresponding powered port?
Test connecting charger to all ports.

Are you using original 87W charger?
Machine turns on with battery connected?

What is the exact PPBUS_G3H voltage?
If missing, remove F7000/1 and check C7050 voltage.
 

phantom

Member
I have 1v1 ldo on All ports

No I’m using my my power bench supply

I’ve no Tried to boot with battery only

I don’t remember ppbus voltage, But i remember it was ok…i will check it for you
 

phantom

Member
i made a mistake: i have done all measurement with my mac m1 air power uspply type c (30w)

PPBUS_G3H is 12,2v with power supply and doesn't turn on with battery only connected
 

2informaticos

Administrator
Staff member
I don't understand what kind of power supply you want to use.
CD3215 chips MUST establish communication with an USB-C charger.
 

2informaticos

Administrator
Staff member
Get original Apple chargers to have in stock; if you really want to stay in this business.

That one may work; check its voltage specifications.
 

phantom

Member
Hi to all...820-01041 no liquid spill...3 usb ports stuck on 5v, the other port totally dead

Because of a small journey, I’ve ask a friend of mine, technician, to change the controller corresponding to the dead port

I don’t know why, I have changed all 4 controller

now i have 5v@0,269 on all 4 ports

According to this guide


I confirm that

i have all ldo's...

i have PPDCIN_G3H
i have TBA_VDDA (PPCHGR_VDDA)
i have PM_EN_P3V3_G3H (NC_CHGR_EN_VR1)
i have PP3V3_G3H

i can't find in schematic PP1V2_G3H_SMC_VDDC or PP1V2_S5_SMC_VDDC
i can't find in schematic PP3V0_G3H_AVREF_SMC or PP3V0_S5_AVREF_SMC
if it is PP3V0_G3H_RTC, i have 3,3v

i can't find SMC_RST, if it is TP_CHGR_SMC_RST_L, i have 1,7 and not 3v

if i connect the upper left or right port to my mac m1, i receive the message

"impossible to use accessory"

if i try to connect the others two ports, nothing happen

please help and sorry for my bad english!
i wrote them before
 

2informaticos

Administrator
Staff member
You've mentioned 5V on USB-C charger, nothing more!
I talk about Main Logic Board.

What is the exact PPBUS_G3H voltage?
Do you get 3V3_G3H_RTC?

What about CD3215 chips LDOs?
Check them in diode mode too; compare readings between all 4 ports.
 

phantom

Member
PPBUS_G3H is 12,2v, and 3v0_g3h_rtc is 3v!

i told you some post before :)

all main ldo are present!

i've checked them using this guide


i've done alle measurement until "SMC_RST"

i've 1,7v on this line, but the guide says that i should have 3v!

thank you for all your help!!
 

2informaticos

Administrator
Staff member
You said to have a dead USB port.
Did you compare diode mode readings on it with the other ports?

Do you get 1V1_LDO_BMC on all 4 ports for sure?
This voltage must appear only on the powered port.
 

phantom

Member
Have you read my first post? I have changed All 4 controllers and now all 4 ports have 5v… no more dead ports

And i confirm i have 1v1 on All 4 ports
 
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