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820-2915 no pp3v3_sus

F

farfan14

Member
hello. i have 820-2915 board. it doesn't have any visual damage. it doesn't have pp3v3_sus.PM_SLP_SUS_L present. please advice me from where should i start? in SMC_BYPASS mode it's started and presents PP3V3_SUS 3.3V!

PM_SLP_SUS_L 3.3V

PP3V3_SUS - 0V no short to ground

P3V3SUS_EN_L 3.3V

PPBUS_G3H is 12.58v with/without battery on 85w charger

PM_BATLOW_L and SMC_BATLOW_L with and without battery have 0v

PP3V3_S5 -- 3.3V
 
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2informaticos

2informaticos

Administrator
Staff member
"in SMC_BYPASS mode it's started and presents PP3V3_SUS 3.3V"
Does it boot then, or just stays on without any activity?

Check AVREF_SMC voltage.
 
F

farfan14

Member
yes its booted in smc bypass mode there is chime, apple logo, loading bar about 60% and than restart and same ....

AVREF_SMC have 3.3v
 
2informaticos

2informaticos

Administrator
Staff member
Then you have problems with some I/V sensor (pages 48 & 49).
Check ohm resistance between pins 17/18 and 27/28 of U7000.
 
F

farfan14

Member
resistance between pins

17/18 is 3.6 ohm and voltage is 12.57v for chgr_cso_n and same 12.57v on chgr_cso_p

27/28 is 21.2 ohm and voltage is 16.v for both chgr_csin/p
 
F

farfan14

Member
during this state SMC_PBUS_VSENSE must be or not ? there is 0v

SMC_DCIN_VSENSE have 2.7v

SMC_CPU_VSENSE 0v

SMC_GFX_VSENSE 0v

SMC_GPU_ISENSE 0v

SMC_GPU_VSENSE 0v

SMC_CPUVCCIO_ISENSE 0v

SMC_SA_ISENSE 0v

SMC_P1V5S3_ISENSE 0v

SMC_CPU_HI_ISENSE 0.6v


SMC_GPU_HI_ISENSE 0.68v

SMC_OTHER_HI_ISENSE 0.68v

SMC_BMON_ISENSE 0.05v

SMC_DCIN_ISENSE 0.2v


SMC_CPU_ISENSE 0v

SMC_GFX_ISENSE 0v

p.s during this testing i suddenly saw that green light wasn't on the charger. i checked ppbus_g3h and is only 0.9-1v. tried detach and plug several times and nothing changed. still 1v. during this 2 days it happenes first time. but now still 1v

update: after several detach and plug now back to 12.58v
 
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2informaticos

2informaticos

Administrator
Staff member
Are you using 85W original Magsafe 1 charger?
Board still doesn't start with both charger and battery connected?

What said the client about how problem appeared?
 
F

farfan14

Member
i don't have another 85w original magsafe 1 charger. is there any method to check possibility of charger problem? can i test by multimeter on the motherboard if charger is not enough for anything ?
 
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