I'm not too familiar anymore with the 280, but if it's an RSC isn't its default ~. and not #.? You should be able to check with /usr/platform/`uname -i`/rsc/rscadm show. It lists escape_char.
resetting the alom from the OS is not possible on a T2000. I've seen the issue you descripted a couple times and it looks related to the firmware version (6.7.4 or older). If you can take the system...