Macbook A3113 - Battery not detected

[tommy97]

Hi,

I have a problem with an A3113 MacBook Air. After liquid damage, the MacBook had no backlight and did not detect the battery. I fixed the backlight circuit by replacing a missing resistor; however, I can’t figure out the battery-charging circuit issue.

Current measurements:

• PPBUS_AON: 12.26 V
• SYS_DETECT_L: 0 V
• SMBUS_BATT_1V8_SDA: 1.8 V
• SMBUS_BATT_1V8_SCL: 0.6 V
• PPVBAT_AON_CONN: 12.26 V measured at the connector

I checked the traces, and they appear to be fine. I also replaced D5190 just in case, but there was no change. The battery connector had significant liquid damage.

I also tried with a fully working battery from another device, same issue.

In the system, laptop shows: Battery replacement required 1%, not charging. Laptop works on battery charge and also on just charger.

[mon2]

Remove all power. Meter in resistance mode. Measure the resistance to ground of the same SMBUS_BATT_1V8_SCL line. If the resistance is not too low then inspect the series resistor @ RD208 = ~0R ohms if ok. Then the pull-up resistor @ RD202 must be present and within spec of the schematic values.

Remove D5150 and test again. The SCL line appears to be shunted to ground from either D5150 being defective from a previous transient or this line is not being pulled up as required by the SMBUS / I2C interface designs.

[tommy97]

SMBUS_BATT_1V8_SCL is on 1.2k OHM, tried without D5150 - same reading.RD208 Is 0OHM, And RD202 Should be 3.3k and my measurement show 1.9k, I2C_SMC_PWR_1V8_SCL_R is also 0.6V

[mon2]

Flux and carefully remove UD200 (level shifter). Then power up to check if the SCL line is pulled high or not. This level shifter may be defective.

[tommy97]

Removed UD200 and it is still the same

[mon2]

Remove RD206 and test if the SMBUS_BATT_1V8_SCL floats to 1v8. If yes, remove all power. Meter in resistance mode. Measure the resistance to ground of SMBUS_CHGR_1V8_SCL (using the smd pad of the removed resistor @ RD206). The regulator @ U5200 may be pulling this SCL clock line down.

Do confirm that the required pull-up resistor @ RD202 is being pulled high to the 1v8 rail.

[tommy97]

While RD206 removed SMBUS_CHGR_1V8_SCL on battery connector 1.8v, On the RD206 SMD Pad 0V

Can RAA489901 be found in any other macbook boards or it is new edition IC?

[mon2]

Appears that you can replace this part which is common to other models as well:


https://www.avenue-mac.com/en/produc...85-a2780-a2992

[mon2]

and this:

https://www.aliexpress.com/w/wholesa...tlist.search.0

[tommy97]

That worked, I used a part from A2465 and it is compatible.