820-4924-A Power troubleshooting (Good Karma Fire damage fix)

brooke.j

Member
This board has been through a fire! Family friend just lost everything in a fire. I was able to retrieve the Data off of the ssd and thought I'd see if I get good karma and try and fix the Macbook too. It looks like there is no actual fire damage just water damage. I've put it through the Crest and afterwards it did show the low battery connected symbol but now I tried giving it some power to work on it and nothing.

Q. Is there a sticky topic on trouble shooting power issues?
 

brooke.j

Member
Well I guess first off I will test the MagSafe. My schematics say 18.5v but I'm only getting 16.5v on PIN 1 and 3.6v on Adapter Sense Pin 6.
 

brooke.j

Member
Ok well I just happened to have another Macbook same model come in and at the magsafe on logic board the voltage is 16.5v. I guess that's normal for schematics to be off that much?
 

brooke.j

Member
PPBUS_G3H = 12.4v
PP3V3_S5 = 3.4v
PP3V42_G3H = 3.4v

Also I no longer get the dead battery symbol when jumping the power on.
 

brooke.j

Member
I watched a video where Louis was trouble shooting a board with no Green/orange light and he tested the PP5V_S3 ( S3 meaning sleep, correct? ) and he got 5v on that rail. How did he get the board to be in a sleep state to test if there was 5V when the board was not powering on?
 

brooke.j

Member
PP3v3_S3 is present
PPBUS_G3H = 12.4v
PP3V3_S5 = 3.4v
PP3V42_G3H = 3.4v

Just no PP5V_S3. I wonder if I could have been an idiot and zapped something when I was trying to jump the power on at SMC on and off. I might have accidentally touched SMC_MANUAL_RST with power. I'm shakey with my hands sometimes.
 

brooke.j

Member
Ok so I've checked but I'm not that great with schematics I guess because all I can find is PP5V_S3_RIO, PP5V_S3RSO_ALCAM, PP5V_S3_ALSCAM, etc. No PP5V_S3 alone. And I can't even figure out where PP5V_S3 starts to check that component. I know how to put PP5V_S3 into Open BoardView and see all the points but that does't help if I can't trace down the path. Thank for all the help do you happen to know the first component to check for PP5V_S3?
 

brooke.j

Member
So if PP5V_S3 comes from PM_SLP_S4_L then where does it do that because I can't seem to find that on the schematics?
 
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brooke.j

Member
Ok thanks for that now I see that PP3V3_S3 is not there. Ok so I have to figure out what makes those which as you tell me comes from PM_SLP_S4_L. Ok so now to see where that starts. When searching a schematic for PM_SLP_S4_L I get 5 pages that have it. Is the first page where it starts and is that true of other lines when searching schematics?
 

brooke.j

Member
I guess my question is.. how do I figure out where something is going when I'm switching pages. Just hit the next button on the search? Thx for the help and sorry if that's a stupid question.
 

brooke.j

Member
Yes I always use real chargers with correct wattage. I've made that mistake before. Arggg ha ha let's not start over. I'm just getting the hang of where to look. LOL! I think I kinda get how to read the schematics now. I see the little page numbers at the end of a line and it looks like that is where those lines go to. so I can now follow the schematic. Also nothings changed other than there is no PP3V3_S3. So let's not start over. What gives power to PP5V_S3 and PP3V3_S3? You said PM_SLP_S4_L . Ok so let's look at that. Looks like system power management maybe?

I have:
Orange/Green light

PPBUS_G3H = 12.4v

PP3V3_S5 = 3.4v

PP3V42_G3H = 3.4v

PP5V_S3 = 0v (measured at Pin 1 of L4001 and many other places)

PP3V3_S3 = 0v

If I can get a direction to go for I'm happy to do the research.
 
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