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820 3462, ppbus = 12.29v

N

Noguinfor

New member
Hey guys,

the client on this machine try to replace the battery and fuck the machine!

When i disassembly the board i noticed that U7000 it's burned! already replace U7000 twice for a new one but PPBUS remains on 12.29V.

measure on c7050 and c7020 = 5.3ohm - 21ohm .

Already replace the SMC from another one and same history!

any advice ??

Thanks
 
2informaticos

2informaticos

Administrator
Staff member
Post diode mode to ground on SCL/SDA lines of battery bus; as voltage too.
If you get more than 1% difference, remove D6950 and test again.
 
2informaticos

2informaticos

Administrator
Staff member
Do you get Magsafe light?
Does the board start at least, or works?

You can remove D6950, just in case.
But I doubt this is the problem.
 
N

Noguinfor

New member
relatively to this one with a original charger (85W) the machine works well! But still have 12.27V on PPBUS!

Already replace D6950 for a new one same history!

Strange problem!

what could be ?
 
N

Noguinfor

New member
Battery not recognize! I have a X on them in osx!

Battery it's new. I have 15.70V on R7020 and 0.5V on PPBUS only with battery!

R7000 = 2ohm
 
N

Noguinfor

New member
Yes, even with enable screw for battery i have ~0.250V!

The Machine runs perfectly with charger connected but don't detect the battery! PPBUS remains on 12.28V.
 
2informaticos

2informaticos

Administrator
Staff member
If PPBUS_G3H stays at 12.3V without battery, your problem is on the MLB.
Once fixed PPBUS_G3H issue (12.5V), then connect battery and see if good.

Post SCL/SDA voltage.
Change SMC again; check SCL/SDA continuity under SMC pads, once removed.
 
N

Noguinfor

New member
OK understood!

before i remove the SMC the voltage on SCL oscillate 3.4V - 3.3V and on SDA it's 3.4V stable! i don't know if it's working properly or not!

After that i remove SMC and check the continuity under pads but seems well!

Now in your opinion should i reball the older SMC or the SMC i bought from donor board i bought on ebay? or should i buy another donor board from ebay?

Thanks
 
N

Noguinfor

New member
i forgot that,
i needed to reconstitute the pads under the U7000 pin12 (PP_3V42_G3A) and pin11 (SCL) can this be the problem? I already tried fix the pads and replaced the U7000 3 times! for me looks well, but.... every time i replace u7000 + pads i always got 12.28V on PPBUS!
 
2informaticos

2informaticos

Administrator
Staff member
Pins 10/11 are for I2C bus and pin 12 is the power for that bus.
So fix that problem, or never get correct PPBUS_G3H; SMC cannot talk with ISL6259!
Also pin 13 (reset) must be always high.
 
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