820-4924-A dead

[Soji]

No light on the MagSafe. But the mb is showing low battery logo on the screen after pressing the power botton.
I discovered that f7005 is out, I replace it and it blew again after Pluged in charger.
I removed u7100 and replace another fuse.
the orange light came on, I installed another u7100 from a donor board, the orange light came on and q7130 started getting very hot.
I removed u7100, Q7130 stopped getting hot.
pls what can I do next. Thanks

 

[2informaticos]

Possibly bad Q7130.
Check diode mode between R7120/50.
If short, change Q7130.

 

[Soji]

There is a short on r7150 (0.001)
Replaced q7130, diode mode to ground on r7150 now is (0.117).
but ppbus is still 1.1v.
U7100 is getting very hot
Q7130 is getting warm.

 

[2informaticos]

I said to check between the both resistors, not to ground!!!

 

[Soji]

Ok btw resistors is 516
But ol on switching probe. , note-this reading is without u7100
After I Installed another u7100 the MagSafe is flashing green light.
ppdcin voltage goes up and down between 13v and 2v
Ppbus is 1.1v.

 

[2informaticos]

PPDCIN_G3H usually fluctuates when leakage is detected.
What happens with lab PSU, or fake charger?

Post U7100 basic voltages; pins 1, 2, 3, 9, 12, 13, 14, 15, 17, 19, 20, 27.

 

[Soji]

1-2.47
2-0.031
3-0.00
9-0.00
12-0.00
13-0.00
14-0.09
15-0.00
17-0.161
19-0.00
20-0.00
27-2.431

 

[2informaticos]

I expected these voltages with lab PSU.
Why would you want to check something which you know doesn't exist with original charger???

 

[Soji]

Psu
1- 0.00
2-17.66
3-4.36
9-0.90
12-3.42
13-3.39
14-3.39
15-0.00
17-12.61
19-5.53
20-5.54
27-18.03

 

[2informaticos]

Exact resistance between pins 27/28?
Check R7121/22 and their traces.

 

[Soji]

0.028
R7121 10.1k
R7122 10.4K
With Lab psu I have ppbus and fanspin.
The traces are good.

 

[2informaticos]

0.028 is close to expected value; should be 20 ohm.
However, R7120/21 can't have 10K each one; 10 ohm is other thing.
Please, post accurate information.

Change Q7180 and test again with original charger.

 

[Soji]

Worked