Star Tech Journal

STAR*TECH JOURNAL/SEPTEMBER 1983
21
SERVICE 'IIPS:
* NINTENDO
VERTICAL ROLLOVER
* BALLY MONITOR
PINS 555 LAMP BURNOUT
* BALLY BABY PAC-MAN FEATURE LAMP BURNOUT
By Sam Cross, Godwin Distributing, N. Little Rock, AR
Nintendo Monitor Vertical Rollover
Problem: Vertical rollover on Nintendo monitors, especially older
Nintendo games such as Donkey Kong and Radarscope. In these
games with the monitor placed vertically, the vertical foldover will
appear on the left hand side. Attempts to adjust this condition out by
the use of the vertical height or vertical linearity controls will result
in frustration. This problem is also likely to appear in later games
such ·as Popeye and Mario Bros., only the foldover will appear at
the top instead of the left side because the monitor is placed
horizontally.
Bally Pins 555 Lamp Burnout
Problem: 555 lamps bum out too quickly on late model Bally
pinballs.
Cause: Feature lamps bum at too high a voltage.
Cure: Install two bridge rectifiers in series to drop the feature lamp
v.oltage approximately 2 volts.
Cause: C407, a lOmfd, 160v electrolytic capacitor with radial
leads has failed. Also, C410, a lOOmfd, 160v electrolytic with
radial leads may need replacing.
Cure: Replace these above mentioned capacitors with the same
types and the same or higher voltage ratings. Both are located near
the back of the monitor PCB. We have had enough of these monitors
come through the shop with the same problem to warrant issuing a
service notice.
Procedure: Referring to Figure 1, cut the blue wires about six
inches above each of the following plugs: pin 5 and pin 8* of J1
(playfield plug), pin 11 of J3 (back box plug). Attach these wires
together which come from J 1 and J3. Also, attach the wires that you
cut loose from these plugs. Insert bridge rectifiers . as shown in
Figure 2. Heatsink these rectifiers!
•
Figure 1: AS-2518-54 Rectifier Board Assembly
e
SW ILL BUS
J3 PIN 11
SW I LL BUS
J1 PIN 5 &
J1 PIN 8
(if pin 8 is used)
HOm
For all Bally pinballs
except Baby Pac-Man,
which uses 555 lamps
HOT£ I
@@
@
"®
(Part of) A2: Power Transformer Module
TO WIRE
HARNESS
*PIN 8 OF J1 MAY NOT BE USED.
BRIDGES SHOULD BE HEAVY
AMPERAGE TYPE (25 AMPS)
Continued on next page.