Star Tech Journal

S•TJDECEMBER198116
BALLY
BURNT
* CONNECTOR * SOLUTION
BY KENNETH R. DUNCAN, MEMPHIS AMUSEMENT, MEMPHIS, TN
Here is my solution for a common problem on
all Bally pins from "Freedom" thru "Strikes &
Spares". As these games age, the general
illumination (AC lamp) connector pins in 12
and J3 on the A2 Transformer Module
(Rectifier PCB) will overheat and burn. As a
result the general illumination lamps on the
playfield and/or backbox (sometimes both)
become intermittant, depending upon the
amount of mechanical vibration induced into
the machine by players. If pins 10 and 11 on
J3 become hot enough the plastic connector
shell warps and pin 8 makes intermittant
contact causing another common Bally problem
with these older games. Pin 8 is the 11.9 volt
input to the 5 volt regulator. An intermittant
5 volts shows up as "power-down" and
"power-up" during game play.
If you remove the two black wires
(transformer terminal 18) and the two blue
wires (transformer terminal 17) from the back
side of the rectifier PCB you will have an easy
way to cure these problems. (See Figure One.)
Remove the two general illumination return
wires from connector 11 (playfield) and the one
return wire from 12 (cabinet-coin door lamps)
and connect them to one of the black wires
from transformer terminal 18. I like to use
butt connectors as this makes it easier to
remove the transformer assembly for service.
If you solder the connections, be sure to use
heat shrink tubing or tape. I use a small
tie-wrap over tape as tape has a habit of
drying out and falling off and we don't want
to tempt Murphy with a potential short.
Follow the same procedure with the two
general illumination return wires from J3
(backbox) and connect them to the remaining
black wire from transformer terminal 18.
Route the wires through the existing harness
for neatness.
Obtain two in-line fuse holders and connect
them to both the blue wires from transformer
terminal 17. You could use a double fuse
block mounted somewhere close to the trans-
former but I don't like to tempt Murphy with
exposed connections. (Players maltreat our
equipment enough without us trying to blow up
the MPU module with 7 .3 volts AC!)
Next we have to connect the buss wires to the
other side of the fuse holders. Remove the
two general illumination buss wires from 11
(playfield) and the one buss wire from 12
(cabinet-coin door lamps) and connect them to
one of the in-line fuse holders. Follow the
same procedure with the two general illumina-
tion buss wires from J3 (backbox) and connect
them to the remaining fuse holder. (I use smal1
flytags to label the fuse holders.) You have
divided the AC lamp circuit in half so use
10 amp fuses in the holders.
Now that you have entirely isolated the AC
lamp circuit from the rectifier PCB you can
replace any burnt connector shells and pins
with the confidence that you will never have
to do it again. Don't forget to amend the
game schematic to show the modification. This
will help other service techs troubleshooting
the game.
Now if only someone would come up with a
foolproof coin mech ...
SOLENOID DRIVER PCB
FIGURE ONE
WHITE WIRE FROM A2J1-1
- - - --
GREEN WIRE FROM A2J1-2
-
--,
- - -- - 1
GREEN WIRE WITH RED
TRACE FROM A2J2-5
I
TRANSFORMER
ROUTE WIRES NEATLY THROUGH EXISTING
CABLE AND LABEL FUSES
2 BLACK WIRES FROM TRANSFORMER TERMINAL
- -- - - - -- ~ - - - - - - - - - - - - - - - - - - _ _ , . , . . . .
GREEN WIRE FROM A2J3-1
- - - - - - - r- - -- - - -- - - - - - - - - - - - - - 1
WHITE WIRE FROM A2J3-2