Star Tech Journal

7
STAR*TECH JOURNAL/SEPTEMBER 1982
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SYSTEM 80 TROUBLESHOOTING * GAME OPERATION * SWITCH MATRIX
GAME START
All three balls must be in the ball return trough to start a game.
1. Insert coins into coin chute.
a. Coin chute tune is played (dependent on Switch #27).
b. Total credits are displayed in status display ( dependent on
Switch #28).
2. Press Credit Button to start game.
a. Credit tune or voice is played.
b. Total credits displayed decrease by one.
3. All playfield features reset.
4. The first player score display flashes a single zero.
5. When the ball is released to the shooter:
a. Playfield-controlled lamps flash.
b. High Game to Date is briefly displayed in all 4 players'
score displays and the lower playfield display.
Problems
Problem 1: No response pushing credit button.
a. Switch
b. Isolation diode
c. No credits
Problem 2: Tune played; displays updated; game over relay
never energizes:
a. No +24vdc
Problem 3: Playfield features reset; ball remains in outhole.
a. Outhole fuse
b. Outhole coil
c. Driver transistor
d. Are all balls in trough?
Problem 4: Ball kicked from outhole; game goes dead while playing.
a. Check slam switch
b. Check +5vdc
c. Check coin switches
SWITCH MATRIX
1. Switch closes: The signal from the control board, strobe,
travels through the switch and its isolation diode and then
back to the control board on a return line.
2. The control board identifies which switches have been closed
and processes each closure in turn,.
3. The game PROM provides the information for score and
feature-related switches (not front door switches or tilt
switches.
4. By careful examination of the matrix returns, the processor
eliminates all switch bounce, yet recognizes all valid switch
closures. Additional components on the switches, such as
capacitors, are unnecessary. Every switch is remembered for
up to 15 closures at one time.
Switch Problems:
Problem 1: One or more switches give no response.
a. Switch adjustment (never closes - never opens)
b. Open diode (jump out)
c. Bad strobe or return ( check other switches)
CAUTION: Turn game power off before making any switch
adjustments. Switches are wired directly to the control board and
must not have more than 5vdc on them at any time.
Problem 2: One or more switches give incorrect response.
a. Shorted strobe or return ( check other switches)
b. Shorted diode
c. Bad PROM (use self-test - step 18, 20)