On 60s and early 70s electromechanicals the point scores sounded a bell or
gong, unlike later electromechanicals which used chimes. The lowest digit
on these games, usually had the bell on the bottom of a stepping unit,
where it conveniently loosened from the constant clanging and fell off, and
was lost. This problem seems to be most common on Bally and Williams
If your smallest point score doesn't make a sound, check the backbox for a
stepping unit usually labeled 'match unit', '0-9 unit', or '00-90 unit'.
This should likely have a bell attached to the bottom. If the bell has
fallen off you'll have to get a replacement. Usually several different
sizes of replacement bells (3 to 3-3/8 inch) will fit and work suitably.
Check also that the unit steps freely and is not sticky or dirty. If it is
sticky or sluggish, which is often the case, you'll have to at least clean
the contacts side of the unit, using rubbing alcohol, and then lube the
contact points using a tiny amount of coin-op lube. In the worst case
you'll have to disassemble the unit, usually because somebody oiled it at
These units often have burned up coils as well. Check that the coil is good
and works strong enough to advance the unit crisply.