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820-3115 no green light

Jeffotskie26

Jeffotskie26

Member
hi i have a1278 before i open the macbook was can on and can charge.
the main problem is when turning on after few seconds
can see the apple logo then suddenly shutdowns then
on automatically then shutdowns again, sometimes u need to turn on again.

found small corroded parts r5481 and r5482
also pin 7 8 U6100 after i clean this part (no parts from here damage)

now no green light but still can on with high fan with battery

no smc bypass mode on charger, on battery yes

testing on charger orig 65watts without battery
PPBUS_G3H 0.0V

u6900
pin 5 0.0V traces goin to j6900 pin5 is ok
pin 4 0.0V
pin 0.0V

checked and change dcin board and u6900 still no green light

u7000
resistance between 17-18 3.2 ohms
28-28 20.3 ohms

voltages:
1 15V
2. 16.4v
3. 3.8v
9. 0.0V
12. 3.4v
13. 3.4v
14. 0.0V
15. 0.0V
17. 0.0V
19. 0.0v
20. 0.0V
27. 15.7V
 

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Jeffotskie26

Jeffotskie26

Member
update:
after changing u7000
resistance between 17-18 3.4 ohms
28-28 20.4 ohms
voltages:
1 0V
2. 17.8v
3. 4.3V
9. 0.3V
12. 3.4v
13. 3.4v
14. 3.2V
15. 12.2V
17. 12.2V
19. 5v
20. 5V
27. 18.3V
can on fan spin high, can on using battery without
charger but cant recognize battery info
no orange light and green light.
(u7000 came from working board tested can charge the battery got orange light from charger)
 
2informaticos

2informaticos

Administrator
Staff member
Do you get 12MHz at Y5010?
Post its DC voltages, if you don't have o-scope, or frequency meter.

Did you try known good DCIN board?
Post U6900 voltages.

Check voltage and diode mode at SCL/SDA lines of battery bus.
If something strange, disconnect BIL and test again.

Do you get 3V3_S5?
 
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