macOS not recognizing the battery

Hey guys,

I've got a customers 2012 MacBook Pro which is not recognizing the battery.

So far I've tried as follows:

I've done everything on this Battery not detected, won't charge; strange connector on logic board? which is more or less

- SMC reset

- reset the PRAM

- disconnect the charger and battery and reconnect in varying different ways

I've also tried 4 different batteries, 3 different chargers and replaced the MagSafe board.

Everything has the same results. Not recognized.

When the computer is off the green LED on the charger continuously flickers on and off.

I read somewhere else that the charging IC may be bad, but I don't know how to test that.

Anybody have any other suggestions?

Thanks,

Eric