K2500RS digital out?

Greetings, everyone. I'm having a bit of difficulty getting any digital audio out of the XLR out on the K2500. I've tried it into several different DAT decks, Digital Betacam, and our digital router. Any suggestions? Is there some operator error here or does the box need to go back to the factory?
BTW, the only analog outputs I'm using are the mix L&R and the headphones.
Thanks for your help!

Make certain that the SAMPLE page is setup properly.

On the sample page.
SRC: INT
MON: OFF

Set the sample mode to DIGITAL. Then you can adjust whether its sending AES/EBU or SPDIF and you can also determin which cable, Optical or COAX. Once these are set, put it back to ANALOG.