Controller freezing when battery connected

Hi,

I've got a weird issue with my controller. All of the sudden it stopped working on my ps4. No button is working.

Took it apart to visually check inside, no sign of damage. Started troubleshooting by replacing the flex pcb and the usb Connector, and the issue is still there

So I started testing while reassembling. The bare pcb worked (not always) as I could move and click the analog stick. Still (not always) working when sitting pcb on flex pcb and connecting touchpad. It is when I connected the battery that the issue reappeared.

Battery is charging normally (drawing 0.26A when connecting controller on my laptop usb port) and is ok. I've tested it fine in another controller.

I could play with the controller tethered to the ps4, but I would like (and try, if possible) to get it fixed.

Any idea please ?