820-2879 No PPBUS_G3H

[Hermann Neupert]

Board is water damage, at first no green light no nothing.
U6990 was damage, R6905, C6990, and small resistor in the area with some degree of damage or oxidation, change all.

Now I have pp3v42_g3h and green light.
Q7080 working fine.
Q7085 don't let pass PPDCIN_G3H
I have 17.56V in pin 1, 2 and 3
and 15.6V in Pin 4
Only 3.7V on Pin 5, with a very little pulse about 0.04V

I have already change Q7085 and U7000, values for R7085 and R7086 are normal.

What else should I check?

 

[2informaticos]

First check resistance to ground at L7030.
Post some voltages for U7000; pins 2, 3, 9, 12, 13, 14, 15, 19, 20.

 

[Hermann Neupert]

L7030 resistance to ground is 454

U7000:
Pin 2: 18.31V
Pin 3: 4.35V
Pin 9: 0.04V
Pin 12: 3.35V
Pin 13: 3.35V
Pin 14: 3.14V
Pin 15: 0.07V
Pin 19: 5.08V
Pin 20: 5.08V

 

[2informaticos]

Post exact resistance between pins 17/18 and 27/28.
Also post resistance value (measured onboard, ohm scale) for R7080/81 and R7085/86.
Did you change Q7085?

 

[Hermann Neupert]

Pins 17/18, resistance is 2.9
Pins 27/28 resistance is 20.2
R7086 is 316 Kohms
R7085 is 468 Kohms
From pin 1 in U7000 to Pin 4 in Q7085 resistance is 801 Kohms
R7080 is 99.3 Kohms
R7081 is 62.5 Kohms

I have continuity from pin 26 in U7000 and R7081

Yes, I have already replace U7000 and Q7085

 

[2informaticos]

Resistance to ground at R7020?
Voltage U7000, pins 1 y 26?

 

[Hermann Neupert]

Resistencia en R7020 to ground = 611

U7000 pin 1 = 15.81V
U7000 pin 26= 16.78V

And I'm using a power supply set at 17.8V (that knob is is a hard to set, so I set it between 17V up to 18.5V)

Hablas espa?ol?

 

[2informaticos]

It should work with bench power supply and 60/85W cable.
But you MUST have an original 85W charger on the service; both styles, Magsafe 1 and 2.

Check all traces and surrounding components for U7000.
Solder another ISL6259, if don't find other things bad; do NOT use ISL6258.

Mejor hablar ingles en el foro.
Asi toda la gente nos puede seguir mas facil...

 

[Hermann Neupert]

I change U7000 (I use a ISL6259 from store.rossmanngroup.com) and Q7085 (from donor board) again, same result.
I took out R7020, and between Q7085 and R7020 is 0.1 V and between R7020 and Q7030 is 1.3V.

So Q7085 is clearly not opening,
Check all resistance around U700 all are good. traces look fine.

I use a 85W original cable in my power supply for both Magsafe 1 and 2, but only have a Magsafe 1 85W original charger.

I will remove R7085 and inject voltage to Q7085 and see if I get to open it.

S?lo preguntaba porque pusiste un "y" en vez de "and", y me dio curiosidad, pero entiendo es solo en ingl?s.

 

[2informaticos]

The current will always flow through Q7080.
No matters CHGR_SGATE level, internal diode is there.

Do NOT inject voltage; CHGR_AGATE should be pulled down.
U7000 probably detects some issue and keeps Q7085 blocked.
Did you test Q7085 out of the board, before solder it?

Post ALL voltages for U7000; a ver si suena la flauta.
Keep F7040 removed, until input stage problem is solved.

"pusiste un "y" en vez de "and""
Bueno, aveces me equivoco; el ingles is not my native idioma.
Tampoco el spanish, ya que soy from Romania