I finally managed to upgrade the screen yesterday, first take-apart.
All went well, and wanted to sync the unit after. No luch, so I found the "great" idea of licking the connectors. Yes, licking.
Bad idea

Now my phone has developed a strange issue: partial mute.
The sound is ON, the ring tones and alarms work, so I CAN use it as a phone.
The PALM part does NOT work, meaning no key clicks, no MP3 playback, no voices from TomTom, in general no system sound at all.
Obviously the speaker itself is not broken. I also doubt that it should be the infamous jack connector for headphones, since sound DOES come out from the phone.
Strangely, another (unrelated ??) issue is that when I open the Camera program, the hotsync function starts.
I did do a hard reset, with a complete format of the unit.
Any clues would be very helpful !!