(347) 552-2258 [email protected]

820-3536 detecting battery but not charging

M

mskzo

New member
Hi,

I'm a newbie trying to repair my own laptop.
The laptop stop working (no green or orange light) and i detected a short on P3V42_G3H due to a short on C5007. Its repaired and the problem gone.

During the debugging process of the problem, accidentally (while trying to find the short) i inverted the polarity of P3V42_G3H (2V only).
Now the laptop is working and detecting the battery but is not charging the battery. It also turns off if i unplug the charger and won't boot without the charger. The battery is ok.

I performed some measurements and i have:


PP3V42_G3H is present on charger, but not on battery

On Battery only:


PPBUS_G3H 1V
PPDCIN_G3H_CHGR 3V
CHGR_UGATE 1 V
CHR_PHASE 0V
 
2informaticos

2informaticos

Administrator
Staff member
First of all, welcome to the forum!

Looks like this battery is fully drained (maybe bad even).
Be sure R7050 is good and check diode mode to ground on SCL/SDA lines of battery bus; voltage also.
Just in case, check R7005 too.

In case like this the best option is
which can fully diagnose the battery and many times recovers it.
 
M

mskzo

New member
Hi,

R7050 - 10k
R7005 - 10 ohm

SCL/SDA liines are SMBUS_SMC_5_G3_SDA?


If yes,

Measured at D7050:

SMBUS_SMC_5_G3_SDA -> OL
SMBUS_SMC_5_G3_SCL -> OL

With the battery connected 0V on each.

The battery is ok. (I tested in another mac)
 
2informaticos

2informaticos

Administrator
Staff member

HOW TO collection

I hope this "How to" collection will help our members. I will possibly modify this post in time, if updates available. Trigger SMC_ONOFF_L (PMU_ONOFF_L): It reffers to simulate power button function, when the keyboard is not connected. We need to do this when we work with the board...
boards.rossmanngroup.com boards.rossmanngroup.com
Read how to properly check diode mode to ground.
Disconnect charger and battery for this.

Check voltage on this bus w/ and w/o battery connected (charger always).

If battery is good for sure, D7050 is suspect.
Depending on your readings, still need to discard R5380/81, U7100, and SMC.
 
M

mskzo

New member
Again diode mode:

SMBUS_SMC_5_G3_SDA -> 0.512V
SMBUS_SMC_5_G3_SCL -> 0.513V

With and Without Battery :

3.46V both
 
2informaticos

2informaticos

Administrator
Staff member
Values look good.
May have problems with U7100, or SMC.
Be sure first, no broken pins/solders/traces on battery connector.
Just in case, change Q7155.
 
M

mskzo

New member
Today, after working normally with the computer (the battery charging problem is not solved yet as I'm waiting for the components) the computer stopped working (no green or orange light).
I inspected the board and now i have found a new problem. The R7020 failed. Can it be related with the charging problem? Is usual a R7020 failure?
 
2informaticos

2informaticos

Administrator
Staff member
R7020 is in the way of 3V42_G3H generation.
Nothing can move on the board without this voltage.
Usually one of C7090-92 is bad, or U7090.
D7005 may be bad too.
Don't forget to check diode mode to ground at L7095.
 
2informaticos

2informaticos

Administrator
Staff member
"C7090-92- OK"
Did you check diode mode there?
Compare with good board.
If good, replace R7020 and test the board.
 
M

mskzo

New member
C7090 in diode mode mesured 0.362V. I can't compare with a good board because i only have this board.
I will try to replace R7020.
Thanks
 
M

mskzo

New member
I replaced the resistor and the board is already booting. Do you suggest replace the caps?
Now i'm facing the original problem (battery 78% but not charging)

2informaticos said:
Values look good.
May have problems with U7100, or SMC.
Be sure first, no broken pins/solders/traces on battery connector.
Just in case, change Q7155.
Click to expand...

is possible to check if the problem is from U7100 or Q7155 without replace the component? (i'm trying to find a scrap board)
 
2informaticos

2informaticos

Administrator
Staff member
A chaman may help to find the culprit without measuring and changing anything on the board.
We try here to help based on measurements and changing suspect components.

macOS shows 78% and machine goes off if charger is unplugged?
 
2informaticos

2informaticos

Administrator
Staff member
Check voltage at battery connector directly.
Again, be sure R7050 is good and J7050 has good contacts and traces.
I hope the battery is really good...
 
You must log in or register to reply here.
Top