820-3115 bad smc?

Bouba148

New member
Hi Guys ,
I received that 3115 board not turning ON with no history, very clean no apparent water damage

PPBUS_G3H: 12.59V
PP3V42_G3H: 3.493V
PPVRTC_G3H: not stable : 3.33V to 3.49v
PP5V_S5: not stable pulsing between 3.5v to 5.0v
SMC_PM_G2_EN: pulsing

At U6901:
SMC_BC_ACOK: 3.353V
SMC_BC_ACOK_VCC: 3.493V

At U6900:
SYS_ONEWIRE: 3.472V

Suspecting U4900 SMC

Put flux and reheated without success.

Anything else to check before reballing SMC?
 

Bouba148

New member
Reballed SMC ( Nighmare job ), and put it back:
Now I'm back were it was:

green Light OK
Pulsing PP5V_S5 and PP3V3_SUS
SMC_PM_G2_EN: pulsing

At U6901:
SMC_BC_ACOK: 3.350V
SMC_BC_ACOK_VCC: 3.492V

At U6900:
SYS_ONEWIRE: 3.470V
 

2informaticos

Administrator
Staff member
Chek if 5V_SUS pulses too, or is short to ground.
Also remove R5805 and see if get stable 5V_S5.
No pulse at all at L7260?
 

Bouba148

New member
5V_SUS also pulses,
Removed R5805, 5V_S5 still pulsing
very light pulses at L7260 from 0V to max 0.04V
Also my DC power supply is "tic-ing" in loop but doesn't go in protection mode (CC)
 

Bouba148

New member
Already tried at the begining and no sign of life

Also removed both Q7840 and U7801 and checked but i'ts still pulsing
 
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