6
STAR*TECH JOURNAL/JULY 1982
SERVICE 'l'IPS:
STERN FLIPPER ASSY'S * WILLIAMS PS CONNECTOR* STEREO VS. MONO
By David "Rock" Bogrees, JCS Coin Machines, Dayton, OH
Stern Flipper Games
The flipper assembly used by Stern had a high frequency of
breakdown. A game that has been on location for a month or two
may have flippers that stick badly. A technician will go on the
call and replace a broken screw in the plunger stop. The new
screw will then work loose because the hole has been battered
into an oval by the old screw before it broke. Countless service
calls will then ensue if the whole bracket isn't replaced. Brackets
are costly compared to the solution that is offered. An 8/32 tap,
tap handle, and some 8/32" x 1/4" screws are needed. After
removing the flipper bracket from the playfield, tap the plunger
stop and the bracket with the 8/32" tap. You now use the 8/32" x
1/4" steel screws to secure the plunger stop to the bracket. These
screws are much heavier than the 6/32" that come stock with all
Stern games. Bally uses the 8/32"s. I have had far less trouble
with their flipper assemblies. Be sure that you don't drill the hole
out larger until you have tried tapping by hand first. Drilling will
make the threads more coarse and the screws will fit more
loosely. I would be sure to take a #29 drill bit along in the rare
case that you may need it. This mechanical modification has
made those problem pinballs very reliable. Note: After writing
this article, I learned from Stern that all games previous to" Split
Second" required this modification. The games after this have
the larger screws in them from the factory. Stern suggests using
case hardened screws whereas I have had no breakdowns using
standard steel screws.
Williams Power Supply Burned Connector
Williams changed their power supply board when "Black
Knight" went into production. This is a great .design with one
minor yet reoccuring problem. The general illumination circuit
fuse (F7) keeps opening. It appears to blow but it is only melting
from heat. The heat is coming from a poor solder joint on the left
side of the fuse on the component side of the fuse clip. This side
of the clip must be removed and cleaned of all oxide. The heat is
also coming from the connector, 3J8 pins 6, 7, 8 and 9 due to an
overloaded molex. The fuse clip should be soldered in well on
both top and trace sides. The connector can be broken and the
wires from 6, 7, 8 and 9 should be joined together and soldered
onto a 16-gauge wire. This wire should go to a wire nut where it is
joined to another 16-gauge length of wire which goes to the hole
from which the burned section of the male connector was
removed.
Stereo Versus Mono
The reason for writing this is that some people aren't sure which
type of extension speaker wiring should be used. Of course, it is
easier and cheaper in the short run to wire for monaural. Taverns
that are large really don't require stereo sound. Medium to small
size locations can benefit from stereo sound. In past years every
record was not made in stereo. Some operators felt that due to
that fact, stereo was just a fad. It is not. People hear stereo at
home on their hi-fi, and in their car on their radio and they expect
it when they go to a bar. When you are competing with a business
down the road, you must have an equal or better product. Rowe
International makes their amplifier with two identical yet
separate channels. There is also a switch to select stereo or
mono. If you have your speakers wired for stereo, you can hear
the difference just be changing the switch. The speakers must be
alternated left and right channels for the proper effect. Room
symmetry must be observed also when placing speakers.
Another major point that should be noted is that on the same
amplifiers there are adjustments for room accoustics. This is in
case the room is a skating rink with a lot of echo or a bar with
carpeted walls and drop ceiling causing a muffled sound. Each
channel can be adjusted individually for bass and treble at
minimum medium and maximum levels. This will bring out the
full capadity of an~ juke box at any location.
PACE'S
FUSED EYELETTING SYSTEM
Pace's PFP-30 Fused Eyeletting System permits field repair of
damaged or missing plated-thru holes and terminals on PCBs
with factory quality.
The PFP-30 is a high reliability system which permits
installation of a variety of hot fused eyelets and funnelets for a
broad range of setting conditions. It also eliminates the solder
"blowout" problems associated with conventional eyeletting
techniques.
The PFP-30 is easy to set up and align precisely; can be used
in a vertical hor horizontal position; and has a long, deep reach
for hard-to-get-at repairs.
Pace's Fused Eyeletting System includes: a fused eyeletting
machine, tool kit, CIR-KIT'" (with pre-tinned/scored eyelets,
TRAK-PADS, etc.), and a hea,zy duty-power source.
Pace's PFP-30 is available from Pace representatives
worldwide. More information may be obtained by contacting:
Marc Siegel, Pace, Incorporated, 9893 Brewers Court, Laurel,
MD 20707. (301) 490-9860.
Save damaged printed circuit boards and assemblies with Pace
lncorporated's Model PFP-30 Fused Eyeletting System which permits
repair and replacement of damaged or missing plated-thru holes and
terminals.