Thanks for your quick response.
Below my answers/ eventhough questions:
Is AMR activated?
No. AMR is not activated on BSS part.
Could be Abis pb (BER, FRAME_ALIGNMENT etc): Is there possible to have high BER only on one TRX ( of course i know that this TRX is not faulty and the cell have 2 TRX defined)?
What about frame alignment/Misalignment?? I mean could frame be misaligned for days even when i changed hardwares?
I will try to reset the corresponding TCU .