HP E4406A OS problem

[R-1125F]

I have an HP E4406A that will not boot properly. The OS is HP-RT.  When it boots it tells me that files and directories cannot be found.   I tried to use the HP E4406A firmware update software through the ethernet port.  The software can communicate with the processor board.  The update software completes and says that the update was successful, but the E4406A screen says it can't erase the memory and create new files (errno = 5).  This uses flash ram and not a hard drive.  I don’t know if this is a software or hardware problem. 

I haven't found a way to communicate directly with the processor through the ethenet port.  I think I need to restore the OS somehow, but I don't know how to do that.  The processor board is similar to the one used in the HP 16702A logic analyzer.  It has ethernet and 488 ports available.  I am totally lost here. 

Could someone give me an idea on how to communicate with the processor without an IP address?

[m k]

Through Ethernet port it is a packet protocol of some sort.
So the receiving end must know how to react.

Maybe you're just missing a voltage somewhere.

[R-1125F]

Thank you for the reply. 
I have determined the operating system (HP-RT) is just gone.   I have no idea how to replace it.   This is essentially an HP9000 computer.
Anybody know how to replace the OS?