Lexmark CX725
975.xx
Network error—Unrecognizable network port.
Replace the standard network card, or the card in the specified slot.
976.xx
Unrecoverable software or error in the network or network card [x].
See Standard network/network card error service check.
978.xx
Bad checksum while programming the standard network or network card [x] port.
See Standard network/network card programming error service check.
979.xx
Flash parts failed while programming the standard network or network card [x] port.
This article shows the primary information required to escalate error codes or messages issues.
Lexmark CX/CS8xx and XC/Cxxxx: 843.01 Error Message