sys1966,
Проверь правильность /var/3g/etc/usbmode.conf
# Huawei E1550
# Huawei E1750
#
# Contributor: Anders Blomdell, Ahmed Soliman
DefaultVendor= 0x12d1
DefaultProduct= 0x1446
TargetVendor= 0x12d1
TargetProduct= 0x1001
# only for reference and 0.x versions
# MessageEndpoint=0x01
MessageContent="55534243123456780000000000000011060000000000000000000000000000"