A1278 13" - Battery not charging, always green, ventilator full on.

I bought this macbook on ebay as a replacement for my other 13' unibody - i have no information about its history. It works perfectly on external power supply (but fans are on full steam).

Apple hardware test detects zero errors. coconut battery shows no values, battery always X out, magsafe always green light, never orange.

I have already swapped the battery, didn't help. SMC reset etc also have no effect.

The previous owner has removed (cut the cable) to the board with the battery charge indicators. I have ordered a new one and replaced it, but this didn't help (and the battery charge is not indicated when i press the button). I also swapped the magsafe connector board. My conclusion, this system has a HW fault on the mainboard. Given the SMC is not diagnosed as defect and the machine works overall, I suspect the charging circuit or charge sensing is gone.

Now ... I unfortunately dont have a board view (and no clue where I could buy it) and am trying to identify the resistors around the i625 - as I suspect it could be a charging current detection issue.

Therefore I just had a look at the i625 chip with a magnifying glass and took attached photo. Looking at it, I am wondering if this doesn't look like remainders of some liquid spill.

Any advice here?

- Does this look like liquid spill to you?

- Who can help me to identify which one is the current detection resistor?

Thanks in advance !