I'm in a big truble.

I'm using Ubuntu 8.04LTS with SW Raid 1. One of the discs faild and system is down. Shoudn't it works with second one as well?
When I try to boot get: No IDE Master H.D.D. Detected!
When I resume, just cursor blinking.
It looks there is no grub on sdb.

Please help, I'm lost