macbook pro A1278 - green light on magsafe - no power

[opethfan]

Hi
i have a macbook pro but it won't power on, only green light on magsafe.
There was a small spot with water and i clean it, and a component in that spot is removed.
See pictures for some measurements...

[yakideo]

Re: macbook pro A1278 - green light on magsafe - no power

What's the logic board code?

[opethfan]

Re: macbook pro A1278 - green light on magsafe - no power

820-2879-b

[highpulse]

Re: macbook pro A1278 - green light on magsafe - no power

well right near the socket for the hdd cable there are 2 pins (smc_on_off ) if you merge the 3.42 g3hot pin with gnd chek if it does turn on

[opethfan]

Re: macbook pro A1278 - green light on magsafe - no power

done, but still doesn't turn on

[opethfan]

Re: macbook pro A1278 - green light on magsafe - no power

on smc on off there are 6.3 volts

[yakideo]

Re: macbook pro A1278 - green light on magsafe - no power

a component in that spot is removed.

The component that is missing on your board is R6995. It's part of a voltage divider for the 3GHot supply. Missing that one might very well not enable the power rail for the SMC. (see https://www.badcaps.net/forum/showthread.php?t=42038 for schematic/boardview)

[opethfan]

Re: macbook pro A1278 - green light on magsafe - no power

i saw that R6995 is a 160 k resistor, can i put a similar like 150 k?

[Th3_uN1Qu3]

Re: macbook pro A1278 - green light on magsafe - no power

That is a voltage divider so it may need accurate values. You can use 150k and 10k in series to get 160k.

[dellxps15]

Re: macbook pro A1278 - green light on magsafe - no power

1/16w
mf-lf
348k
1%
r6995
402

the bigger one near 0402 is :

R5001
OMIT
0
MF-LF
603
5%
1/10W

[qonma]

Re: macbook pro A1278 - green light on magsafe - no power

we have same problem
only light green in magsafe
the fan not on
can help me

[Pinoyku66]

Re: macbook pro A1278 - green light on magsafe - no power

820 2879 does not turn ON, have a green light ion mag safe. Found S0 enable is missing
PM_SLP_S3_L missing( supposedly 3.4volts?) os zero volts but this signal coming from U1400 CPU, what else I need to check, please help.
Very much appreciates the response.

[ZHEMZ]

Re: macbook pro A1278 - green light on magsafe - no power

first measure Current Sensing Resistors around U7000 . if all good then check POWER RAILS to find out what Power Rail is missing ...