Charging problems

Status
Not open for further replies.

JorgePayar

Member
Hi, I nearly "fixed" a 820 3115b, It passed all ASD tests, EFI...hardware tests...with no errors, but I can see that when I plug an original apple charger, sometimes charge, sometimes not, even the light shows green but after a few seconds the led turns off, but in OS it says that is charging but it is not really.
What could it be?smc?
 

leonattpcs

New member
So is the the 1 wire issue damage/fault to the connector or is it wear and tear on contacts causing lack of electrical contact?
 

JorgePayar

Member
Ok, I started checking continuity with some caps around u7000 and resistors, the macbook pro wasn't connected to the charger, I tested the continuity only half second in c7050 and u7000 did a short and fried!! I had to replaced it and now it recognize when I plug the charger but it says that the battery is not charging :( I don't know what I did wrong
 

larossmann

Administrator
Staff member
Measure resistance between pins 17/18, then measure resistance between pins 27/28. The resistance between the pins should be NO GREATER than the resistance of all the resistors in the circuit, so for example R7050/R7051/R7052, and R7020/R7021/R7022. If the resistance is greater than the total resistance of the current sensing resistors, then either a trace is blown, a via bad, or a resistor bad.

This may help put it into perspective as well.

https://www.youtube.com/watch?v=vgeVpYWkwBM
 

larossmann

Administrator
Staff member
BTW, a fucked up ISL6259 can short the current sensing section to ground and kill the sense resistors.
 

JorgePayar

Member
Thanks for the hints :)
Ok I have measure them and pins in ISL6259 17-18 are: 141,1 Ohms pin 27-28 are: 0,20 Ohms, then R7050 0,001Ohms R7051 139,6 Ohms (probably fucked up R7052 0 Ohms
R 7020 0 Ohms R7021 10 Ohms R7022 10Ohms I´ve been measuring others around the u7000 area and they look good as the schematics says.
So I think I have to change the resistor r7051, or do you think could be a blown trace?
 

JorgePayar

Member
I´ve replaced r7051 but It keeps saying the same the OS: "the battery is not charging" :( bad u7000? ?bad trace?? stupid repair guy (me)? I think could be the last question :)
Any more ideas?

Edit: Ok now Im watching this video: https://www.youtube.com/watch?v=PtEDoMV5oe8 and Im going to check for bad traces around u7000
 
Last edited:

JorgePayar

Member
Ok Im going to explain myself better, so the computer switches on without charger and it recognizes the battery but it does not charge the battery itself.
I already checked all traces around u7000 and they are all good, so what can be?
 
Last edited:

JorgePayar

Member
So is the the 1 wire issue damage/fault to the connector or is it wear and tear on contacts causing lack of electrical contact?
No, all contacts seems to be ok, I use the same charger for another macbook pro and it is fine, the connector from the battery is fine too, works well.
 

D_R

New member
What's your current value of the Resistance between pin 17 and 18? And what voltage do you have on Pin 17 and 18? I would also suggest to remove the C7050 for testing.
 

JorgePayar

Member
What's your current value of the Resistance between pin 17 and 18? And what voltage do you have on Pin 17 and 18? I would also suggest to remove the C7050 for testing.
current value resistance between pin 17 and 18 is 2.6 Ohms without plugin in. Voltage plugged in the charger is pin 17= 4.08 pin 18= 4.08
 

D_R

New member
It has to be 18.5V. <= I talk about Pin 2 on U7000
Have you checked F6905 and D7005? What Voltage do you have here?
 

aprendiz

Moderator
with a 60W charger this voltage is ok, measure in diode mode F7040 red probe to ground.............check sense resistors R7020-R7021 and ACIN
 
Status
Not open for further replies.
Top