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MBA 2013 - 820-00164 - not charging - orange light

U

uli

New member
Hello,
my daughter's MB ceased to charge after she twisted the cable from a charger that it got shorted which fired a house breaker. The computer worked until the battery went dead.

  • The orange light is on, but it draws only around 65 mA.
  • The computer cannot be started with or without a battery connected on a adapter, but I suppose it would start if the battery was charged. I don't have a spare one.
  • When I do reset (Ctrl+Opt+Shift+Power) the light turns green for a few seconds and then again gets back to orange.

What should I measure? Can I create some external circuit to charge a battery to check the function?

Thank you
Uli
 
U

uli

New member
PP3V3_S5 is dead zero. Not beeping to the ground, only short capacity beep.
PP3V3_SUS is, if I understand the boardview correctly, available from the other side. I will be able to disassemble the computer in few days.

Thanks
Uli
 
Last edited:
2informaticos

2informaticos

Administrator
Staff member
Post U7501's basic voltages: pins 23, 22, 12, 13, 29, 21.

Just in case, check diode mode to ground on all big coils.

BTW, write directly into bottom reply box, instead of clicking Reply button.
Please, maintain forum aesthetic...
 
U

uli

New member
Hello,

PP3V3_SUS has nothig, 0.003 mV respectively.

U7501:
23 3.090 V
22 3.085 V
12 3.420 V
13 1.997 V
29 3.037 V
21 3.420 V

Coils to ground both ends (value after settling down):
L7320 14ohms beep
L7310 14ohms beep
L7430 ol short capacity beep
L7630 346ohms short capacity beep
L7130 ol short capacity beep
L3095 ol
L7701 ol
L7560 ol short capacity beep
L7520 ol


Just to be sure - I am feeding it 14.85V as written on the apple power supply. I have just the mainboard connected with magsafe board over J9500 and J7000. It is my first MacBook repair.

Thanks
Uli
 
2informaticos

2informaticos

Administrator
Staff member
Impossible to get OL in diode on any coil.
Just check again with RED probe connected at GROUND.

"L7310 14ohms beep"
14 ohm is correct reading for CPU core.

BTW, no need to check on both pins of a coil to ground.

"23 3.090 V"
Are you sure PPBUS_G3H is only 3V???
 
U

uli

New member
Appologies for my mistake. So the diode to the ground with red on the ground. I have used the beeper.

L7320 0.0233V
L7310 0.0233V
L7430 0.238V
L7630 0.177V
L7130 0.153V
L3095 0.533V
L7701 0.431V
L7560 0.370V
L7520 0.440V

And the PPBUS_G3H is realy 3.09V.

Thank you
 
U

uli

New member
The C7140 voltage is slowly oscilating between 3.08 - 3.30V after F7140 removal.

Just to be clear, battery is not connected.
Although, the orange light is on.
 
Last edited:
U

uli

New member
The battery is removed and also the F7140 is still removed.

U7100:
1 0.0242V
2 13.3V
3 3.87V
9 0.033V
12 3.416V
13 3.383V
14 3.383V
15 0.0705V
17 3.215-3.268V oscilating
19 4.988V
20 4.742V
27 0.745-0.750V fluctuating

Also, the current drawn is little higher then in the beggining, if it makes any difference, now 74mA.
 
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U

uli

New member
R7180 100.4 kOhm
R7181 61.4 kOhm
R7185 471.1 kOhm
R7186 331.7 kOhm

Resitors look good according to schematics.

I made also D-S diode test on 7/8/9/10 -> 1/2 and 7/8/9/10 -> 4/5 on Q7180 with result around 0,52V. Opposite OL.
All other D-S-G combinations were OL with beeper.
 
U

uli

New member
Q7180:
1/2 14.755V
3 5.998V
4/5 17.235V
6 14.108V
7-10 14.773V

I have also tried to measure current sensing circuits and R7150/1/2 look good. R7120 looks also good, but R7121/2 have strange readings. Like 5.5kOhm and 324 kOhm. Definitely not 10 Ohm.

Also, the fuse is still removed.
 
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2informaticos

2informaticos

Administrator
Staff member
Replace R7121/22 and check their traces to R7120.
Also check diode mode to ground at pins 27 & 28 of U7100.
If all good, check again C7140 voltage.
 
2informaticos

2informaticos

Administrator
Staff member
You can resolder F7140.

R7121/2 can be replaced with 4.7-22 ohm resistors; even direct bypass will work.
Be sure first no short on pins 17 & 18 of U7140 to ground; C7121/2 suspects in such case.
 
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