Helix (3xxx) Enhanced Keyboard, firmware upgrade and power supply

Hello,
I got a problem with the enhanced keyboard of my Helix.
Some time ago, I discovered that it can't see my power supply but both batterys are working fine. It's not à PSU problem as my helix see it just fine.
Where it become annoying is that I can't upgrade the firmware of my keyboard as the updater say I need to plug the PSU.
I already tested with another PSU and even reseted the keyboard with no luck.