820 00165 No Power

EJS

New member
820 00165 no power, board has 2 tiny spots of liquid damage on Q7630 and U1930. Magsafe lights, 8.57v on PPBUS. PP5V_S5 is present, when I measure voltage for PP5V_S3 at L4011 and R6414 I get 0, but when I take a measurement at L4605 I get a reading that jumps all over, very strange. I have replaced U1930 due to it looking like shit.
 

2informaticos

Administrator
Staff member
Do you get 3V3_SUS?
If not, check PM_SLP_SUS_L.
PM_SLP_S4_L pulsing at least?
L7520 should pulse at same time.
If yes, check if other coils pulse too.
Is better to check toggling SMC_ONOFF_L signal; use R5115/16 pads for this...
 
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EJS

New member
PP3V3_SUS 3.346v stable
PM_SLP_S4_L 0V no pulsing at least that I can seen on my Fluke, I dont have a scope
SMC_ONOFF_L 3.427v stable
 

2informaticos

Administrator
Staff member
"Is better to check toggling SMC_ONOFF_L signal; use R5115/16 pads for this..."
You need to see any reaction.
 

EJS

New member
2info, I dont understand what you are asking me to do. Are you telling me to short the pads?
 

EJS

New member
Yeah, unfortunately im still getting no change bridging those pads.
 
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2informaticos

Administrator
Staff member
Check S5_PWRGD, PM_DSW_PWRGD, PCH_DSWRMEN, SMC_ADAPTER_EN, PM_BATLOW_L.
Does MLB start on SMC bypass mode?
 

EJS

New member
S5_PWRGD 3.399v
PM_DSW_PWRGD 3.426v
PCH_DSWRMEN 3.248v
SMC_ADAPTER_EN 3.426v
PM_BATLOW_L 3.343v
Not sure what you mean by SMC bypass mode, but I cant get this board to do anything as far as turning on.
 

2informaticos

Administrator
Staff member
"i get about 2 seconds of fan spin"
That means L7520 gets voltage in this time.
Check which other big coils get voltage...
 

EJS

New member
L7520 is not getting 5v, for those 2 seconds that the fan spins, I get a different voltage each time it comes on anywhere between .855-4.3v
 

2informaticos

Administrator
Staff member
So L7520 pulses; you can see 5V with o-scope, not DC multimeter.
Check which other coils pulse too...
Also check if ALL_SYS_PWRGD pulsing?
 
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