If (on a DigiBeta DVW-A500 or similair) you enable menu item 105 - Ref Alarm - the stop lamp will flash under several conditions;
- The reference signal is solid and the input video is locked but there is more than 43 video lines offset between them - the a longer period than the VTR's pre-read system will tolerate,
- The reference signal is solid and the input video is unlocked.
- The reference signal is solid and there is no input video and the deck is locked to video rather than ref
- There is no reference