Midway Pac Man Troubleshooting Logic Board Part 1 General Instructions

							                       METHOD OF PLAY
SW. #1SW. #2
OFF ON1 COIN1 PLAY
ON OFF1 COIN2 PLAY
OFF OFF2 COINS1 PLAY
ON ONFREEPLAY
                      NUMBER OF PACKMEN PER GAME
SW. #3 SW. #4
ON ON 1 PACKMAN
OFF ON 2 PACKMEN
ON OFF 3 PACKMEN
OFF OFF 5 PACKMEN
                                     BONUS PACKMEN
SW. #5SW. #6
ON ON BONUS PACKMAN AT 10,000
OFF ON BONUS PACKMAN AT 15,000
ON OFF BONUS PACKMAN AT 20,000
OFF OFF NO BONUS
SW. #7SW. #8
OFFOFFPLAY MODE
ONOFFRACK TEST
OFFONLOCKS PICTURE
          MO51 -00932-A035
ELECTRICAL BULLETIN: FOR ALL APPARATUS COVERED BY THE CANADIAN
STANDARDS ASSOCIATION (CSA) STANDARD C22.2 NO. 1, WHICH EMPLOYS A
SUPPLY CORD TERMINATED WITH A POLARIZED 2-PRONG ATTACHMENT PLUG.
CAUTION:TO PREVENT ELECTRIC SHOCK DO NOT USE THIS (POLARIZED)PLUG WITH
AN EXTENSION CORD, RECEPTACLE OR OTHER OUTLET UNLESS THE
BLADES CAN BE FULLY INSERTED TO PREVENT BLADE EXPOSURE.
ATTENTION:POUR PREVENIR LES CHOCS ELECTRIQUES NE PAS UTILISER CETTE
FICHE POLARISEE AVEC UN PROLONGATEUR. UNE PRISE DE
COURANT OU UNE AUTRE SORTIE DE COURANT, SAUF Sl LES
LAMES PEUVENT ETRE INSEREES A FOND SANS EN LAISSER
AUCUNE PARTIE A DECOUVERT.
                                            2 
						

							PAC – MAN
TROUBLE SHOOTING LOGIC BOARD PC A082-91375-A000
1. CHECK +5VDC 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 TESTSWITCH.
12. SWITCHES #7 AND #8 MUST BE OFF FOR NORMAL GAME PLAY.
13. SWITCH #7 ON WILL TEST RACKS.
14. GOOD LUCK!
4 
						

							PAC – MAN
TROUBLE SHOOTING
 PC A082-91375-A000
NOTE: All I.C. trouble shooting information is with the I.C. removed from circuit.
POSITIONCHIPPOSSIBLE TROUBLE
1-E74LS161All Characters are at top of screen - Characters move
horizontally only.
1-F74LS283Lines and Squares entire screen - Effects Self Test.
1-H74LS283Horizontal lines across screen in color.
1-K74LS283No Sounds - Game plays normal.
1-L74LS174Same as 1-K
1-M5623 (Prom)Same as 1 –K
1-NCD 4066Same as 1 –K
2-A93415 (Ram)Effects Color of all Characters - Game plays.
2-B93415 (Ram)Same as 2-A
2-B93415 (Ram)Same as 2-A
2-D93415 (Ram)Effects Color of the Characters - Eyes only two
Characters.
2-E74LS161 Characters top of screen - Characters move
horizontally-Effects Game Play-Color 8. Sound OK.
2-F74LS283Effects Self Test - Row of Characters horizontally
across screen. Effects Game Play-Color & Sound OK.
2-H74LS86All Characters are Squares - Effects Self Test –
Horizontal Color Bars across screen.
2-K74LS89Effects all Sounds - Game plays & color OK.
2-L74LS89Same as 2-K
2-M74LS273Same as 2-K
2-P74LSO2Effects Sync - No Video - No Sound – Moving
Diagonal Lines.
2-R74LS161Vertical short lines in color - Effects Game Play.
2-S74LS161Horizontal Color Bars across screen - Effects Game
Play.
5 
						

							POSITIONCHIPPOSSIBLE TROUBLE
3-A74LS158No Characters in maze.
3-B74LS157No Video (Dead)
3-D74LS75Characters missing in maze - Game plays without
seeing Characters.
3-E74LS20No Video (Dead)
3-F74LS89Same as 3-D
3-H74LS89All Characters move jerking - Characters do not stay
in maze.
3-K74LS158No Sounds - Game Plays.
3-L74LS157No Sounds - Game Plays.
3-M1M5623No Sounds - Game Plays.
3-N74LS74Effects Sync - Color Diagonal Lines.
3-P74LS10No Video (Dead)
3-R74LS161No Video (Dead)
3-S74LS161Effects Sync - Diagonal Lines.
4-A1M5623 (Prom)No Video (Dead)
4-B74LS377Distorted Letters - No Color - Maze is White –Effects
Game Play.
4-C74LS00No Video (Dead)
4-D74LS273No Maze - Screen covered with Number Fives – No
Letters - Characters moving about.
4-E74LS157Distorted Maze - Letters Upside Down – Characters
Distorted.
4-F74LS86Distorted Characters - Letters and Sound.
4-H74LS245Flashing White Dots - No Color.
4-K2114 (Ram)All White Zeros on screen.
4-L2114 (Ram)Flashing Numbers and Letters in Color.
4-M2114 (Ram)Blank screen with a Single Zero at top of screen –Two
Red Characters Only.
4-N2114 (Ram)All White Zeros on screen.
4-P2114 (Ram)Flashing Self Test - Flashes continuous.
6 
						

							POSITIONCHIPPOSSIBLE TROUBLE
4-R2114 (Ram)Screen is blank with a Number One flashing – A single
Character can be seen.
5-A74LS157Blue Screen - All Characters are Squares – No Letters
or Numbers.
5-B74LS194Color Squares around each Character - All maze dots
are blue.
5-C74LS194Effects Maze - Characters have Squares around
them - Self Test in Red.
5-E9332 (Prom)Blue screen with Horizontal Squares - No Maze – No
Letters or Numbers random Characters.
5-F9332 (Prom)Effects Characters in Maze which are Squares –
Everything else normal.
5-L74LS139Red screen flashing with all Letter F’s.
5-M74LS74Screen covered with Garbage in Color.
5-N74LSO8Effects Sync - Moving Diagonal Lines in Color.
5-SNVC 284 (Custom)Flashing White Dots - Game plays.
6-BZ80 CPUScreen covered with Garbage in Color.
6-DNVC 285 (Custom)Same as 6-B
6-E9332-B (Prom)Flashing blue Zeros and Garbage – Continuous Meter
Pulses.
6-F9332-B (Prom)Blank screen with a Flashing Number One – Bad Rom
One.
6-H9332-B (Prom)Screen covered with Garbage.
6-J9332-B (Prom)Blank screen with random Characters.
6-R74LS367Screen flashing with Garbage in Color.
6-S74LS367Same as 6-R
7-F7603No Video (Dead)
7-H74LS08Eleven Horizontal rows of Zeros across screen.
7-J74LS138No Video (Dead)
7-K74LS138No Video (Dead)
7-L74LS02Same as 7-J
7-M74LS139Screen covered with Garbage in Color.
7-N74LS42Same as 7-J
7 
						

							POSITIONCHIPPOSSIBLE TROUBLE
8-A74LS107No Video (Dead)
8-B74LS368Same as 8-A
8-C74LS74Effects Sync - Diagonal Lines flashing.
8-D74LS367Effects Dip Switch settings.
8-E74LS367No Coin - No Up & Down Controls - 1st Player.
8-F74LS367No Controls - 2nd Player.
8-H74LS367No Test Switch - 1 & 2 Player Select.
8-K74LS259Stays in Self Test-Shows Memory OK.
9-C74LS161Screen covered with Garbage in Color.
10-A LM377 - LM1877No Sounds.
ADDITIONAL DEVICES
10-ADip SwitchEffects Coin Play - Number of Pat-Man Bonus
Pac-Man.
B-7Crystal (18.432)No Video (Dead)
P-8 (IR1)78GVIC (RegulatorEffects + 5 VDC
R-9D44VM4Pass Transistor - Effects + 5 VDC
L-9D40K1Transistor - Effects Coin Counter
C-92N3391Transistor - Effects Power Reset
8