A1398 820-3662-a Not charging

[TBFix]

Hi laptop had liquid spill as is now not seeing/charging the battery. I have reballed the Smc and replaced u7100 as I was not getting SMC_BC_ACOK. Readings on the batt connector are
pins 1-4 = 4.3v
pin 5 = 3.3v
pin 6 = 3.3 - 0.21v
pin 7 .276 - .019v

 

[2informaticos]

Post diode mode (red probe at ground) on both SCL/SDA lines.
Be sure R7050 is good.

 

[TBFix]

Hi forgot to mention Sda line was short because of U7100 so changed that and sda came back up, (both sda/scl .53) I also had Checked current sensing resistors and continuity to u7100 and was good. R7050 is ok 10k

 

[2informaticos]

If battery is not even detected, there is a problem with battery bus.
If you have an o-scope, check for pulses.
If diode mode readings are equals on both lines, then probably bad SMC.
Be aware of battery connector; sometime corrosion underneath can block the bus communication.

 

[TBFix]

What should pin 7 read ? as it still read pin 7 .276 - .019v even without battery. I have scope there are pulses on sda line.

 

[2informaticos]

Pin 7 must be kept low through R7050; it enables the battery.

You must have pulses on SCL too.
Did you try known good working battery?

 

[TBFix]

Scl does not pulse that I can see on scope. I dont have another batter to compare unfortunately. And no donor board of same number to try a different SMC.

 

[TBFix]

Does the Smc have to come from exactly the same board or are some inter-changeable?.

 

[JohnB8812]

Yes has to come from 3662 board

 

[2informaticos]

ALWAYS use SMC from same donor model.
Sometime board can start with different SMC, but you will get weird issues; only solved by correct SMC.