820-00165 Charging Issue

Ludedude1992

New member
Hope you can help. I have a 2015 MacBook air with the 820-00165-A board. The issue I'm having is the battery will not charge. Computer runs fine on wall adapter and the computer sees the battery. I tried another battery with the same result. I'm a bit new at this but catch on fast. I already have the board view for this board and have started troubleshooting.

PPBUS_G3H is 8.4v so I assume Q7155 is the issue. Is there a way for me to test Q7155? Anything else I should be checking?

Additionally I am using coconutBattery to see the Charging info. When I first attach the charger it shows charging at 10 watts then gradually drops to 0 watts.

Any help would be great.

Thanks
 

2informaticos

Moderator
Staff member
Any history available?
Post voltage for U7100, pins 9, 15, 26.
Measure onboard exact value (ohm scale) for R7180/81 and R7185/86.
Do you get amber light when charger is connected?
Do you have original Apple 60/85W charger, MagSafe 2 model?

OSX shows some message like Replace/Service now for battery?
 

Ludedude1992

New member
As far as history goes not much other than being informed of the charging issue. Board looks clean. Water indicators all white.

On U7100 it appears there may be some corrosion between pins 8 and 9. Anyways here are the read outs.

U7100
Pin 9 - .03v
Pin 15 - 8.56v
Pin 26 - 14.59v

7180 - 100.3k
7181 - 62.2k

7185 - .466
7186 - .331

Amber light shows on charger even with battery unplugged

45 mag safe 2 oem charger being used

No messages. Battery shows good.
 

Ludedude1992

New member
As far as history goes not much other than being informed of the charging issue. Board looks clean. Water indicators all white.

On U7100 it appears there may be some corrosion between pins 8 and 9. Anyways here are the read outs.

U7100
Pin 9 - .03v
Pin 15 - 8.56v
Pin 26 - 14.59v

7180 - 100.3k
7181 - 62.2k

7185 - .466
7186 - .331

Amber light shows on charger even with battery unplugged

45 mag safe 2 oem charger being used
 

2informaticos

Moderator
Staff member
"Amber light shows on charger even with battery unplugged"
Normal behaviour. MagSafe light will switch back to green only if battery is 100% charged.

Try another charger, 60/85W if possible.

"Pin 26 - 14.59v"
Should be 0V in normal mode.

"Pin 15 - 8.56v"
Really???
Check again that...
 

Ludedude1992

New member
"Amber light shows on charger even with battery unplugged"
Normal behaviour. MagSafe light will switch back to green only if battery is 100% charged.

Try another charger, 60/85W if possible.

"Pin 26 - 14.59v"
Should be 0V in normal mode.

"Pin 15 - 8.56v"
Really???
Check again that...
I'll check again when I get home from work today.
 

Ludedude1992

New member
"Amber light shows on charger even with battery unplugged"
Normal behaviour. MagSafe light will switch back to green only if battery is 100% charged.

Try another charger, 60/85W if possible.

"Pin 26 - 14.59v"
Should be 0V in normal mode.

"Pin 15 - 8.56v"
Really???
Check again that...
I just cleaned up the area again.

Pin 26 is 0
Pin 15 also 0 now
 

Ludedude1992

New member
Well I guess I am going to try reflowing the chip. After cleaning it good with alcohol I am now successfully charging the battery BUT only charging at 1.84 watts. I assume there is additional corrosion that I cannot see.
 

2informaticos

Moderator
Staff member
Give time to fully charge it and take a look to the time reported.
Post again pin 9 & 15 voltage.

Please, do NOT quote an entire post from few cm above; is not aesthetic...
 

Ludedude1992

New member
I double checked. This thing seems to act differently Everytime power is applied as far as u7100 goes

Pin 9 - 3.4v
Pin 15 - .07v


C7125 looks good

Q7155 pin 1 is 1.58v

R7113 looks good
 

2informaticos

Moderator
Staff member
Yes, both charger and battery connected.

"Pin 9 - 3.4v"
Are you really sure?
That is overcurrent on charger side.
Double check R7121/22 and theyr traces to R7120 and U7100.
 

2informaticos

Moderator
Staff member
"With battery connected"
Should I suppose charger is connected too?

"Pin 9 2.15v"
Still too high.
As per schematic, 1.4V means more than 8A; imagine 2V how much is...
So
"Double check R7121/22..."
 
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