SLES 11 SP3 won't boot after applying latest updates
I have a SLES 11 SP3, OES 11 SP2 server running on a Dell PowerEdge 1950. I had last applied updates in December of 2015. I ran the zypper command today to apply the latest updates and it finished without any errors, letting me know that the server would have to be rebooted. I rebooted the server and after the grub menu comes up and the default option times out, I get a black screen with no cursor or anything else. Ctrl-Alt-F1 through F8 doesn't bring up any other screen.
I then tried to boot choosing the grub failsafe mode however I get the exact same results.
This is a simple system with two partitions on a single disk. /dev/sda1 is the swap partition and /dev/sda2 is the root partition. The grub boot loader is calling the partitions by UUID; not by name. During boot I hit ESC on the Grub menu then edited the startup line to call the disks by name; ie "root=/dev/sda2". Still no luck.
I get no error messages; just a blank screen. I can boot from a rescue disk and then mount the root file system and browse it without a problem so the disk appears to be OK.
Any ideas what happened or how to troubleshoot it?