820-3462 low ppbus no green light

[2informaticos]

PPBUS_G3H must appear, even if no Magsafe light present.
Post ISL6259 voltages; pins 1, 2, 3, 6, 9, 12, 13, 14, 15, 17, 19, 20, 27.

 

[Yoel Ren]

1 0v
2 16.5v
3 3.9v
6 3.3v
9 0v
12 3.4v
13 2.4v
14 2.9v
15 300mv
17 1v
19 5.4v
20 5.4v
27 1v

 

[Yoel Ren]

pin 1 is 0v, i look another post is at least 16.5v, and I have changed q7080 before fyi

 

[Yoel Ren]

resistance 17/18 : 3 ohm 27/28 20 ohm
diode mode L7030 : 0.466v
r7025 is good at 0.1 ohm
c7025 is not shorted.

 

[2informaticos]

"c7025 is not shorted"
Does this mean to have good capacity???

Check R/C networks from pins 5, 7, 8.

 

[Yoel Ren]

yeah good capacity, diode mode to ground on pin 1 of c7025 is 0.533v, pin 2 0.121v
r7042 : 0 ohm
r7015 : 99k ohm
r7016 : 3 kohm, all good according to schematic

 

[Yoel Ren]

i usually look for another post as reference, but low ppbus's post is too limited..
i can assure u7000 soldering is good, maybe the chip itself is bad ?

 

[2informaticos]

Possibly, change U7000.

 

[Yoel Ren]

i have changed u7000 multiple times, but all same, ppbus is still at 1-1.1v.. im rather sure the problem isnt u7000 then

 

[2informaticos]

Remove F7040 and check voltage at L7030.

 

[Yoel Ren]

1.1v at l7030 with f7040 removed.

 

[2informaticos]

"27 1v"
I don't know why I didn't see it before...

Change Q7080.

 

[Yoel Ren]

changed q7080, ppbus back 12.26
changed smc, ppbus 12.6v
thanks a lot, solved..

 

[2informaticos]

You're welcome, good job!