RM600 mainframe issues

Hi, I got a Siemens-Nixdorf Sinix RM600 mainframe consisting of a terminal and two cabinets, the SY53 (Zentraleinheit) and the BG54 (I/O Beisteller). For ease of transport I had to cut a 50-wire cable that was connecting the two cabinets, but now the cable has been put together again. Well, I fire it up and I see on the screen that it's going through a number of tests (cpu, memory, adapters). All is ok till it comes to the booting point. There it fails with the following complains Warning 51763 ios0/scon00 Poll fails. Command response block not valid Warning 33243 ios0/scon00 Controller initialization fails. Command response B SASH error: unable to access SASH root device ios0/sdisk000s0 /stand and it returns a limited SASH shell. Since I am assuming that the ios0/sdisk000s0 device is the hard disk on the I/O cabinet, I guessed that there was something wrong with my home-made replacement of the 50-wire cable. I power it down, go to lunch and get back to find out that, when turned on, random weird characters and symbols are displayed on the screen. It looks like that it entered a sort of editor mode, as it shows a top line in which rows and columns are counted. This top line reads ON LINE | FDXA | R=10 | C=5 | AUX=NONE After a while it hangs. I didn't touch a thing since my almost-ok first boot, I only remember to have played a bit with the console keyboard. Any ideas? shall I call the assistance number at the back of the unit? :-) thanks mirko