macbook pro 820-3462 charges very slowly

[donnos]

Received a macbook pro which in notification shows 7 or 10 hours until full during charging.

have replaced ISL6259 and Q7055 and still getting same results. current sensing resistors measured fine @ 0 and 2ohms. what else could be the issue?
without battery i get 12.58V. i have physically shorted Q7055 drain to source to rule out issue with the mosfet and can confirm its still the same. any suggestions?

when i shutdown it charges at only 16.5v 0.5A. during boot PSU draws 2.5-3A suggesting it momentarily charges but drops to 1.5A power draw after boot.

[mon2]

Re: macbook pro 820-3462 charges very slowly

Confirm the voltage to ground of:

SMBUS_BATT_SCL
SMBUS_BATT_SDA

[donnos]

Re: macbook pro 820-3462 charges very slowly

both Diode reading are 0.4 red on ground

[mon2]

Re: macbook pro 820-3462 charges very slowly

Ok. Post the DC voltage to ground of the same. Meter in DC volts mode (10v or higher is ok). Wanting to confirm the SMBUS lines for this segment are ok.

Also, remove all power and meter in resistance mode.

Measure directly at U7000 pins for the resistance between CSOP and CSON. Had this exact case last year and it took ~3 weeks to resolve. The fault was that the current sense loop was broken. The fault was only caught after a direct probe at the U7000 IC pins.

It is important to check that this current sense loop is ~2 ohms (pin 17 & 18 of U7000).

[donnos]

Re: macbook pro 820-3462 charges very slowly

SMBUS lines are 3.34v

CSON to CSOP resistance is 3ohms.

[donnos]

Re: macbook pro 820-3462 charges very slowly

issue resolved by replacing SMC