My IBM server is running RHEL 6, and it cannot boot up. The BIOS seems to be OK (since I was able to go in to change the boot order), and during boot-up, it will stop at a black screen with a picture of a diskette, and arrows pointing to what seems like the F1 key. I'm not sure what this means, and multiple restarts gave me the same problem.
You have problem in boot sector. If you have a partition table backup, restore it, otherwise there are applications to fix it. Some partition table editors can do it.