Easy fix: I believe that you said you're using a 584C panel.
Check fuses 7,8,9, and 10
There are many fuses on the back of the panel. Lamp steady, lamp flash, and lamp wink are provided, via the interrupter, through fuses that are further split up into 4 groups of 3 or 4 line cards at a time.
If the blown fuse(s) are not immediately evident from a visual inspection (sometimes the fuse wire breaks right at the point where it is welded to the body of the fuse), you need to test for an open fuse.
In rare cases it might be a bad interrupter. I just called my old partner to verify that between us, in a combined 70 years of service, we changed maybe three interrupters each during our careers.
