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recieved this macbook a1425 with no visible corrosion
no green/orange light. no fan spin
PPDCIN_G3H 16.4v
PPBUS_G3H| L7030 0.149 1.0V
sometimes orange light shows but nothing changes on the voltage
(changed q7080 twice)
U7000
pin: diode to ground | voltage
1 0.656 0.0v
2 0.601 16.4v
3 0.540 3.9v
9 0.726 0.0v
12 0.321 3.4v
13 0.501 3.3v
14 0.487 3.1
15 0.732 0.0v
17 0.147 1.1v
19 0.334 5.4v
20 0.330 5.4v
27 0.624 1.1v
 
Last edited:

2informaticos

Administrator
Staff member
With 0V at pin 1/U7000, Q7080 is on; should have voltage at R7020.
Change again Q7080 and check all traces.
First be sure R7085/86 are good.
 
after changing again q7080
now i got 12.2v on PPBUS_G3H
r7020 16v
still no green/orange light also no spin.
SMC issue?
 
Last edited:

2informaticos

Administrator
Staff member
Did you try another DCIN board?
Check continuity from U6900 te central pin of Magsafe connector.

Post voltage and diode mode to ground at SCL/SDA lines of battery bus.
 

2informaticos

Administrator
Staff member
Do you get correct 12MHz oscillation at SMC_XTAL/EXTAL?
If no o-scope available, post DC voltage at least.
 

2informaticos

Administrator
Staff member
Looks good; not 100% sure (as o-scope), but usual DC levels, when Y5010 oscillates.

Check other voltages and signals of U4900 (2 OF 2) from page 39.
If good, then change SMC.

Once SMC is removed check continuity for its pads to surrounding components; especially for SMC_RESET_L signal.
 
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