820-3115-B No Battery Detection

mdc2018

Member
820-3115-B No Battery Detection

I have noticed:

R5280 has a resistance of 1.5 instead of 2 , resistor itself is fine

Testting at R5280 seems to be where the problem lies if I am not mistaken.

PP3V42_GH3 = 3.4V
SMBUS_SMC_5_G3_SDA = 2.6V

What controls R5280?

I am relatively new, I apologize if I ask any "dumb" questions.

Thank you!
 

2informaticos

Administrator
Staff member
R5280/81 are the pull-up resistors for SM Battery Bus.
Check resistance to ground on both lines.
Diode mode, red probe to ground; must get less than 0.5-1% difference...

If notice difference, remove D6950 and check again.
First of all, disconnect BIL conector, J6955.
Post the values found.
 

2informaticos

Administrator
Staff member
Still bad...
Did you disconnect J6955?
Next step, desolder ISL6259, let the board cool down and measure again.
If still get difference, SMC issue...
You can try reflow SMC first, or reball it.
But you'll need to change it I suppose.
 
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