Star Tech Journal
Issue: 1982-July - Vol 4 Issue 5 - Page 9
9
STAR*TECH JOURNAL/JULY 1982
American
Arcade
Technical
Academy
GREMLIN/SEGA
"TURBO" MODIFICATIONS
Problem: Noisy Audio
Solution: Remove R215 and R283 from the Sound Board (PIN 800-0123)
Problem: Accelerator test shows only 0, 1, 2 in Self-Test.
Solution: Some "Turbo" units do not provide full accelerator control. Recently,
all Gremlin/Sega distributors have been given a simple rework kit to take care of
that very problem. This is the procedure:
1. On the Accelerator Mechanism IC Buffer Board (PIN 834-0104), located on
the mechanism itself, exchange the two 1 OK ohm resistors for the two 22K
ohm items provided in the rework kit. Rerun the self-test sequence.
2. If the problem persists, adjustthe power supply voltage to 4.8 VDC at full load,
or 5 .1 VDC at no load.
Problem: Game time setting doesn't change.
Solution: On page 5 of the "Turbo" Owner's Manual (PIN 420-0681) add the
following notes:
1. When the CPU Board DIP Switch # 1 is set in the "SKILLED" position,
game time is automatically set to 55 seconds. Option switch settings have no
effect.
2. Regardless of"Game Time" option selection, the displayed countdown begins
at 99 seconds, but does vary its rate of countdown according to option
selection settings of DIP Switch #2 positions 1 & 2.
3. DIP Switch # 1 position 5 is an option used for game testing purposes. Set in
the " OFF" position, the game will operate normally. Set in the "ON"
position, however, your car will not crash. In other words, DIP Switch # 1
position 5 is an "endless game" option.
Problem: The game fuse blows when the volume is turned up full
Solution: Add a 200 ohm ¼ W resistor to pin-1 of each volume control pot, and
add a 3.3K ¼W resistor in series to pin-3 of each volume control pot. This will
solve the problem.
Courtesy of Gremlin/Saga's Service Newsletter "DATA BUS"
MIDWAY
"PAC-MAN" TROUBLESHOOTING STEPS
Troubleshooting Logic Board PC A082-91375-AOO0
1. Check +Svdc at CPU and ROMs.
2. Reset line pin #26 of CPU normally high and goes low with reset.
3. 6MHZ clock frequency at pin # 13 of 8-B and 3MHZ at pin #6 of CPU.
4. Check ROM test for a memory failure.
5. Check all address and data lines at CPU.
6. Check all address and data lines at 4-A and 7-F color proms.
7. Check all address and data lines at 5-E and 5-F character ROMs.
8. When character ROM 5-E is removed, game plays but maze is missing.
9. When character ROM 5-F is removed, game plays but Pac-Man and ghost
monsters are blocks of color.
10. When all program ROMs are removed, the screen will be rows of blue
diagonal lines.
11. Check sounds and switches using test switch.
12. Switches #7 and #8 must be off for normal game play.
13. Switch #7 on will test racks.
14. Good Luck!
* In-depth
instructions on
*
*
*
*
solid state game
equipment
Concise 6-day
course, including
textbooks and
technical manuals
Beginners course:
Second Monday of
each month
Advanced course:
Fourth Monday of
each month
Newly expanded
lecture staff
headed by Richard
Turner, former
field service
engineer,
instructor of
electronics at
California
Community
College, military
instructor/
supervisor,
and owner of an
electronic
maintenance
service.
4688 Alvarado Canyon Rd.
San Diego, CA 92120
Call now for information:
(714) 287-4263
(In California)
(800) 854-2521
(Nationwide)
Credit cards accepted.
STAR*TECH JOURNAL/JULY 1982
American
Arcade
Technical
Academy
GREMLIN/SEGA
"TURBO" MODIFICATIONS
Problem: Noisy Audio
Solution: Remove R215 and R283 from the Sound Board (PIN 800-0123)
Problem: Accelerator test shows only 0, 1, 2 in Self-Test.
Solution: Some "Turbo" units do not provide full accelerator control. Recently,
all Gremlin/Sega distributors have been given a simple rework kit to take care of
that very problem. This is the procedure:
1. On the Accelerator Mechanism IC Buffer Board (PIN 834-0104), located on
the mechanism itself, exchange the two 1 OK ohm resistors for the two 22K
ohm items provided in the rework kit. Rerun the self-test sequence.
2. If the problem persists, adjustthe power supply voltage to 4.8 VDC at full load,
or 5 .1 VDC at no load.
Problem: Game time setting doesn't change.
Solution: On page 5 of the "Turbo" Owner's Manual (PIN 420-0681) add the
following notes:
1. When the CPU Board DIP Switch # 1 is set in the "SKILLED" position,
game time is automatically set to 55 seconds. Option switch settings have no
effect.
2. Regardless of"Game Time" option selection, the displayed countdown begins
at 99 seconds, but does vary its rate of countdown according to option
selection settings of DIP Switch #2 positions 1 & 2.
3. DIP Switch # 1 position 5 is an option used for game testing purposes. Set in
the " OFF" position, the game will operate normally. Set in the "ON"
position, however, your car will not crash. In other words, DIP Switch # 1
position 5 is an "endless game" option.
Problem: The game fuse blows when the volume is turned up full
Solution: Add a 200 ohm ¼ W resistor to pin-1 of each volume control pot, and
add a 3.3K ¼W resistor in series to pin-3 of each volume control pot. This will
solve the problem.
Courtesy of Gremlin/Saga's Service Newsletter "DATA BUS"
MIDWAY
"PAC-MAN" TROUBLESHOOTING STEPS
Troubleshooting Logic Board PC A082-91375-AOO0
1. Check +Svdc at CPU and ROMs.
2. Reset line pin #26 of CPU normally high and goes low with reset.
3. 6MHZ clock frequency at pin # 13 of 8-B and 3MHZ at pin #6 of CPU.
4. Check ROM test for a memory failure.
5. Check all address and data lines at CPU.
6. Check all address and data lines at 4-A and 7-F color proms.
7. Check all address and data lines at 5-E and 5-F character ROMs.
8. When character ROM 5-E is removed, game plays but maze is missing.
9. When character ROM 5-F is removed, game plays but Pac-Man and ghost
monsters are blocks of color.
10. When all program ROMs are removed, the screen will be rows of blue
diagonal lines.
11. Check sounds and switches using test switch.
12. Switches #7 and #8 must be off for normal game play.
13. Switch #7 on will test racks.
14. Good Luck!
* In-depth
instructions on
*
*
*
*
solid state game
equipment
Concise 6-day
course, including
textbooks and
technical manuals
Beginners course:
Second Monday of
each month
Advanced course:
Fourth Monday of
each month
Newly expanded
lecture staff
headed by Richard
Turner, former
field service
engineer,
instructor of
electronics at
California
Community
College, military
instructor/
supervisor,
and owner of an
electronic
maintenance
service.
4688 Alvarado Canyon Rd.
San Diego, CA 92120
Call now for information:
(714) 287-4263
(In California)
(800) 854-2521
(Nationwide)
Credit cards accepted.
Future scanning projects are planned by the International Arcade Museum Library (IAML).