Thanks Mania, but this issue appears only in the room where i installed the repeater (indoor antenna, the serving cell is stable in other room. I have verified all your recommandation:
balanced HORXLVDLI / HORXLVDLO, HW suspected changed, same tilt in GSM/DCS, TX power=0 for all TRX. I have remark: the serving cell is stable near the indoor antenna (5m) then since unstable at 7m even the coverage is good ( RXlev=-69 dBm). What can I do for it?