VECTOR: Asteroids Deluxe 6.3VAC weirdness

Working an Asteroids Deluxe upright.  Looking at the schematics, the only
places the 6.3VAC is used is on the monitor connection (monitor fillament
voltage) and the coin door.  When both connectors are unplugged, I measure
6.3 on both connectors.  But should I plug either one (or both) in, the
voltage immediately drops to zero at all locations (connectors and
transformer).

Any ideas?  I believe the 6.3 doesn't come out of the audio reg, it's direct
from the transformer, so it's not the audio reg.  I guess I can try another
transformer, unless someone may have a tip on what to look for on this
transformer.

Which leads me to one other question, is there a quick/easy guide to
identify the different Atari transformer blocks (i.e., b/w raster, b/w x/y,
color raster, color x/y)?

Thanks,

Joe
[email protected]