If you boot your box to a linux (or *bsd if you prefer) prompt you can check the master boot records of the drives. Most sensible RAID software uses partitions to store the data instead of raw disks so it is perfectly possible for a drive in a RAID array to have been initialized correctly while still containing a valid master boot record, thus making the SS4200 try to boot from it.

To boot to the prompt you'd need a null-modem cable, a terminal and the aforementioned linux or bsd installtion on either the DOM or on a USB stick or -drive. Hit F3 in the BIOS screen to get to the boot manager, select whatever device you have your linux or bsd on and boot that. Now use a partitioning tool to examine the drives (/dev/sda (or sdb or ...) in linux). Does the drive contain a valid partition table? Does this partition table contain a partition covering the whole drive? If that is the case you can safely wipe the master boot record using dd:

dd if=/dev/zero of=/dev/sda (or sdb or...) bs=440 count=1

This writes 440 zero-bytes to the first block on the drive, wiping the master boot record code area but keeping the disk signature and the partition table intact. If you also want to overwrite the disk signature you'd use 'count=446' instead of 'count=440'.

If you are wary of fiddling with your disks in this way you are a) right as a slip of the finger can cause quite a few headaches and b) in luck as you can just as easily make a backup copy of the master boot record and partition table using dd:

dd if=/dev/sda (or sdb or...) of=/path/to/your/usb/stick/or/dom/mbr.backup bs=512 count=1

This creates a backup copy of the mbr and the partition table in the file you entered for the 'of=' parameter.