its hard to plug the charger to turn it on, I mean 9 out 10 times I plug the magsafe, the light is dim green, and sometimes it can turn on 1 out of 10 attempt, and it can boot, but doesnt show battery ( X ), I already used known good battery, with battery indicator light flex unplugged, I suspect it is the smc, because of the intermittent green and dim green light, any idea?
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820-2879b not detecting battery X
- Thread starter Yoel Ren
- Start date
You must get it start always on charger only.
Try first known good DCIN board.
Post U6900/01 voltages and check their traces.
Also post exact PPBUS_G3H (no battery), 3V42 and SMC_RESET_L.
Once machine works properly with charger only, you can continue to fix the battery issue.
Try first known good DCIN board.
Post U6900/01 voltages and check their traces.
Also post exact PPBUS_G3H (no battery), 3V42 and SMC_RESET_L.
Once machine works properly with charger only, you can continue to fix the battery issue.
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maybe the dc in is just not seated properly, ppbus_g3h =12.3v without battery
I would say the board already turned on at least 90% of the time
the ball of this board's smc looks a bit deflated from the usual, is it normal ?
u6900/1 : its 3.2-3.4v not really stable, and it would drop to 0v every 20s
pp3v42_g3h : I have pp3v42
smc_reset_l : 3.4v
I would say the board already turned on at least 90% of the time
the ball of this board's smc looks a bit deflated from the usual, is it normal ?
u6900/1 : its 3.2-3.4v not really stable, and it would drop to 0v every 20s
pp3v42_g3h : I have pp3v42
smc_reset_l : 3.4v
"u6900/1 : its 3.2-3.4v not really stable, and it would drop to 0v every 20s"
Each chip has 5 pins; of course ground pin no need to check.
Post exact voltage and diode mode (red probe at ground) on SCL/SDA lines of battery bus.
Each chip has 5 pins; of course ground pin no need to check.
Post exact voltage and diode mode (red probe at ground) on SCL/SDA lines of battery bus.
pin 11 of u7000 smbus_smc_bsa_scl 0.468
pin 10 smbus_smc_bsa_scl 0.452
pin 11 voltage is stable 3.4v
pin 10 also 3.4v but not stable, it will drop to 0v every few second and back up to 3.4
JohnB8812 yeahh I have bil unplugged, still 12.3v
I actually tried lifting the U4900(SMC?) up and place it back again, still the same condition as before
pin 10 smbus_smc_bsa_scl 0.452
pin 11 voltage is stable 3.4v
pin 10 also 3.4v but not stable, it will drop to 0v every few second and back up to 3.4
JohnB8812 yeahh I have bil unplugged, still 12.3v
I actually tried lifting the U4900(SMC?) up and place it back again, still the same condition as before
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452 and 468 too big difference.
Did you check when SMC removed?
If no difference, bad SMC; change it, reballing doesn't help.
If still difference, remove U7000 and check again.
Also check without D6950.
BTW, let always SMC at the end.
Is more easy to replace U7000, than SMC.
Did you check when SMC removed?
If no difference, bad SMC; change it, reballing doesn't help.
If still difference, remove U7000 and check again.
Also check without D6950.
BTW, let always SMC at the end.
Is more easy to replace U7000, than SMC.
Why do you waste the time?
How many times was explained here how to change a SMC???
How many times was explained here how to change a SMC???
Get SMC from donor board, same model.
Something happened when changed it.
Possible bad solders, reflow it; reball again, if still the same.
Also try starting in SMC bypass mode.
Possible bad solders, reflow it; reball again, if still the same.
Also try starting in SMC bypass mode.
When you remove SMC, SCL/SDA values should go higher than before.
I attached some old notes about 2879 board.
You will find different values, but in the same class; depending what is soldered on these lines.
I attached some old notes about 2879 board.
You will find different values, but in the same class; depending what is soldered on these lines.
Incorrect voltage and SMC is not satisfied; that's the reason machine runs slow.
Battery still not recognized on OSX?
Did you try known good battery?
Disconnect BIL and try again.
Post exact diode mode and voltage at SCL/SDA lines of battery bus.
Check if R7000 is OK.
Battery still not recognized on OSX?
Did you try known good battery?
Disconnect BIL and try again.
Post exact diode mode and voltage at SCL/SDA lines of battery bus.
Check if R7000 is OK.