820-4924 no green led

raainxx

Member
Hi,
i have this board very clean, no green led (PSU and official charger)
I have
PPBUS_G3H=12,27V
PP3V42_G3H_REG=3,42V
DCIN_ISOL_GATE = 6,8V
PP18V5_DCIN_ISOL = 18,5V
SYS_ONEWIRE=2,85V ???
R7012 = 68Kohm
thanks
 

2informaticos

Administrator
Staff member
Does the board turn on?
Try disconnecting LIO flex too.

Post voltage and diode mode to ground at SCL/SDA lines of battery bus.

Any history fault?
Do you get 3V3_S5?
 

raainxx

Member
no the board don't turn on.
i have just the board and the magsafe board. i haven't green led, i don't connect the battery, it's easier to measure voltage on board.
SCL/SDA lines at 0V, SCL/SDA=0,5V in diode mode
the customer close the mac open for the night and the morning nothing, the mac doesn't start.
PP3V3_S5 = 0V
 

2informaticos

Administrator
Staff member
Oops, this is A1502 machine, no LIO board there, sorry.
RIO board present instead.

"SCL/SDA lines at 0V"
Are you sure?
You've said 3V42_G3H is present; where these lines are pulled-up through R5380/81.
Impossible with reported diode mode readings; unless both resistors are open.
Please check again.
 

raainxx

Member
ok i change the board and now i have the green led but nothing.
all-sys-pwgd=0
SMC_RESET_L=0V
PP3V3_S5=0
PP5V0_S5=0
SMC_ONOF_L=3,3V
SMC_TPAD_RST_L= 3,4V
SMC_MANUAL_RST_L=2,8V strange no?
maybe it's U5110? or SMC?
 

2informaticos

Administrator
Staff member
First clean J6100; remove if needed.
If SMC_RESET_L still low, remove U5110 and check it again.
If not present, be sure R5100 is good.
If still low, then remove R7100 and check it again.
SMC is the last thing to test.
 

raainxx

Member
I change U5110 and R5100, sometimes the SMC_RESET_L come to 3,3V and the mac start normally.
I try to remove R7100 but same, i have SMC_RESET_L=1,4V
When i remove U5110 and R7100, i have fluctuant from 1,4v to 2,8V on SMC_RESET_L
 

raainxx

Member
no the connector is very clean (under microscope in and out).
Do you think remove connector is useful if it is clean?
 

2informaticos

Administrator
Staff member
If you are sure about J6100, only SMC remains.
There could be corrosion under it, or internal problem.
Should reball it first.
Once SMC is removed, check if SMC_RESET_L is steady high; with all other components resoldered.
 
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