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820-2850 wont charge

2informaticos

2informaticos

Administrator
Staff member
12.3V means SMC doesn't work correctly...
Do you get green light on magsafe?
Check battery bus lines to ground and voltages.
 
A

aprendiz

Moderator
SMC_RESET_L is present??? If yes, this is a bad SMC.... Was this water damage in the first place??? Apply some flux and heat to see if it come back to life...
 
D

dukefawks

Administrator
It is a data bus issue. Could be battery/ISL/SMC/battery indicator. Anything connected to SMBUS_SMC_BSA is suspect.
 
nate8organic

nate8organic

New member
okay iv narrowed it down to the SMBUS_SMC_BSA_SDA. voltage there is varying from 115v up to 350v over and over.

im getting a solid 12v on the R5280. so is this the isl because im not 100% sure if the r5280 goes directly to the isl..

Also now wile i was testing near the isl the charger light has gone from green to nothing. but now im getting 114v on R5280 after the green light stopped working.
 
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nate8organic

nate8organic

New member
yeah same thing i was thinking. now that my green light is gone, i checked the probe for SMBUS_SMC_BSA_SDA and now im getting a solid 96mv. also the board wont power on anymore. i was testing voltage near the r5280 when the green light went off.
 
2informaticos

2informaticos

Administrator
Staff member
Stop using auto-range.
Use cheap multimeter in 20V scale, avoid any missunderstood this way...
Post PPBUS_G3H and 3V42 values now; voltages and resistance to ground too.
 
larossmann

larossmann

Administrator
Staff member
It seems like you have a short to chase on PPBUS_G3H. My guess is shorted Q7535/Q7530. Inject 1v on PPBUS_G3H, try and find what gets hot. I feel like full story is missing here, first you went from it turning on but SMBUS issue where SMC couldn't tell ISl what voltage to set, now it's dead...
 
larossmann

larossmann

Administrator
Staff member
I missed that. I'm glad we have our newly registered puppy to correct me. Your measurements make no sense and are fucked. I can't give you advice until measurements start to make sense again.
 
nate8organic

nate8organic

New member
larossmann okay i figured i had a short on the ppbus_g3h. i'm not sure what i did to make it dead but im pretty sure i must have shorted something together when i was testing voltage. this board came in from a customer who was changing his battery left a screwdriver on the board that was on the u7000 and got the think pretty dang hot he said. i replaced the isl and all was good but not long after it stopped working not sure what happened.

Im aware that these mesurments are not making sense also, but im getting these readouts so im hoping this things is not fucked hahah.

if i cycle through the range options its showing me .99 ohms to 1 ohm. not sure why im getting 1 ohm..

2informaticos of course im not testing with power.

Update: i tested 3v42 on the u7000 im getting 0.8 ohms to ground and a solid 3.39v with power. i double check the ppbus_g3h and im getting close to 1v not that thats any better. the ppbus_g3h if i set the meter to 0L. k it will give 160 ohms dropping, and normal setting shows 0.
im not sure whats wrong or (what im doing wrong) but i could take a video of the test for oversight.

r5281 pin 2 @0.03v
r5280 pin 2 @0.09v these are not within there 5% range if i understand correctly not sure that they have any importance right now but just adding to the info.

BTW Thanks for taking the time to help me in my struggles here! much love!
 
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nate8organic

nate8organic

New member
i have no power connected to the board. no battery and no power supply just a board nothing connected. did you want me to test the voltage also with no power to the board? i am familiar with testing boards resistance/ voltage.

im not sure why i'm getting 1 ohm with proper voltage so i'm wondering if this may have something to do with things not working.

i also should note that when the green light stopped coming on when i'm guessing i shorted something together next the the u7000, it also fried the power i/o and when i was testing other boards i noticed this and swapped it out for a new one. i dont know if that helps shed any light on things, (i forgot to mention this in the intro)
 
D

dukefawks

Administrator
It is impossible to have 3V42 present and have a 1 Ohm short. No idea what you are doing, please learn how to use a multimeter.
 
nate8organic

nate8organic

New member
Okay im not sure what is happening. i am including videos of my test, please let me know what/if im doing something wrong here so i can improve/correct my mistake(s). As far as i know i know how to use a multimeter, iv only had 2 instances where the auto-range affected my results.
 
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