Keyboard Work only with Battery off and PSU plugged in

The keyboard does not work, no backlight and no pressure, only the volume mute led lights up when I turn down the volume from windows. Hi, I'm going crazy, I took the pc 20 times apart. The laptop keyboard works ONLY if I disconnect the battery flat cable (SO04XL) and connect the power supply to the PC. I turn on and the keyboard works completely. I keep the power supply connected and I also connect the battery flat and the keyboard no longer works. I unplug the power supply and go only with the battery, the keyboard doesn't work.

Sems to be a battery fault (for me) becouse of, without battery the keyboard work. So, I replaced both the keyboard and the battery with new parts in stock (same serial for both the battery and the keyboard), no second hand.

The keyboard ran on battery only for one day. Then he started doing as before. The behavior is the same, the same. The keyboard works ONLY if the power supply is connected and the BATTERY is disconnected.

any suggestion?