WORKING

MS PACMAN

Abbreviation Example:

2A p1 short to p2

Chip 2A pin 1 is shorted to pin 2.

Low means grounded.

High means +5V

M(red, pink, cyan, gold) are the monster colors from top to bottom.

WORKING

Vertical pieces of the maze scroll across from right to left. Shape of the pieces will vary.

Fast moving vertical lines from top to bottom. Caused by shorting the 6 MHz clock signal.

Chip 3D p4 or 13.

Horizontal bars across screen. Size and color of bars will vary.

Fast moving short vertical lines covering screen. High pitch squeal from monitor. Caused by shorting 6 MHz clock signal to other chip pins.

2B shorted 6 MHz clock signal p14 to p9,10,11,12,13 or 15.

2A short p14 to pad next to it.

No sync for the monitor.

2S p11 V Sync low

Fast moving long vertical lines from top to bottom in two columns. High pitch squeal from monitor.

Chip 2A,2B,2C,2D 6 MHz clock signal pin 14 is grounded.

Distorted maze.

Blue tornado moving quickly from right to left. Can also be a solid blue block with the score and credit ok.

3A bad or missing.

Will not boot. Orange garbage on screen. Making a repetitive noise on and off.

Random garbage on screen.

Problem with 5F ROM.

Random blocks of garbage on screen.

Board will not boot. Screen covered with zeros. Top row changes to different letters and a single object changes in the center as the board tries to boot.

Board will not boot. This is just one of the 3-4 screens it shows trying to boot.

Just a few random objects on the screen.

Board will not boot. This is just one of the 3-4 screens it shows trying to boot.

Board will not boot.

Light red haze over entire screen.

Signal from 4A p11 to 3A,3B p11 high.

Red Background

Signal from 4A p12 to 3A,3B p14 low.

Red background between score and credit. No characters.

Red screen, blocks for characters, score and credits.

Thick green haze.

This is most likely caused by your monitor. If you have a known good monitor then:

Thick red haze.

This is most likely caused by your monitor. If you have a known good monitor then:

Thick blue haze.

This is most likely caused by your monitor. If you have a known good monitor then:

Graphics are blocks. Characters are ok.

White background, red maze, blocks behind characters.

5C Removed

Pink background, pink maze, red maze outline. Blocks behind characters. Yellow behind score and credit.

5B removed

Entire screen is blue. Sounds and game still function.

Blue box with black blocks where characters are. Score and credit ok.

Red or yellow box. Sounds ok.

2C p7 short to p5,6,8 yellow.

3D p6 low yellow.

2D p7 short to p5,6,8 red.

Red or yellow box on screen. Score and credit ok.

2C p7 short to p1 yellow.

1 Bar on top half of screen. Score is ok.

2C short p15 to 9 yellow.

2 Bars on screen.

2C short p15 to p10 yellow.

4 Bars on screen.

2C short p15 top11 yellow.

8 Bars on screen.

2C short p15 to p12 yellow.

16 Bars on screen.

2C short p15 to p13 yellow.

32 Bars on screen.

2C short p7 to p2 yellow.

64 Bars on screen.

2C short p7 to p3 yellow.

128 Bars on screen. Hazy shade of Yellow or Red over entire screen.

2C short p7 to p4 yellow.

Entire rows of characters cloned from the left to the right side of the screen.

All characters are chopped in half with their base on top of their head and stuck on the top row of the game maze below the score.

1E or 2E bad or removed.

1E p15 short to p16.

No characters on screen. Dots can be seen being eaten. Caused by interfering or grounding databus RA0 thru RA5.

These can be found on 2A,2B,2C,2D p2,3,4,11,12,13, or 1E p11,12,13,14 or 2E p13,14.

2B p1 is high, or p2&3 or 3&4 or 4&5 shorted.

2A p12&13 or p11&12 shorted.

2E short pin7 to p10.

1E, 2E p15 shorted to p 11,12,13,14.

3D Bad or Removed.

3A, 3B p1 low.

3B p1 short to p8.

Signal 3E p6 to 3A,3B p1.

All characters are stuck in the lower center quarter of the screen.

All characters look like their being transported in Startrek. Characters become lines going from the top to the bottom of the screen and still move from left to right.

1E or 2E p9 grounded or shorted to p15.

Characters ride over the maze edges and move jittery.

Fine horizontal washboard black lines through maze and characters.

2B p4 short to p7

Very boxy maze with no characters.

1E or 2E p1 short p2,3,4,5,8.

1E p15 short to p10.

Medium horizontal washboard black lines through maze and characters.

Vertical black lines and characters move jittery.

Big horizontal washboard black lines through maze and characters.

Sandy Pink maze and dots. No characters.

3B p1 short to p4.

Only score and credit shows. No maze or characters.

2B p1 short p to p7.

2A,2B p15 is low.

2A p1 short to p7.

All yellow maze. Red & cyan monsters are black. No Ms pacman.

3B p9 short to p12.

White cherries

Black maze, white maze outline, white monsters, blue ms pac, red score & credit.

Yellow maze border no characters.

Yellow maze. Yellow on top of midway logo. Pink monster is red, yellow is cyan. Green eyes yellow pupils.

Signal from 4A p11 to 3A,3B p11 low.

White monsters stuck on bottom of screen below credit. Score and credit are faintly seen on the left and right edges.

3A p12 short to p15.

Row of characters stuck on bottom below credit. No other characters on the rest of the screen.

All red maze outline. No characters, no score or credit.

3B p1 short to p2,5.

Red outline on maze. Cyan monster is red, yellow is pink. Eyes are blue, no pupils. Top of midway logo is blue.

Signal from 4A p10 to 3A,3B p5 low.

Red & blue or Red & white horizontal bars thru monsters and game over. Maze is also lightly striped.

Character ROM databus outputs CD0 thru CD7 are grounded.

5B,5C p3,4,5,6

5E,5F p9,10,11,13,14,15,16,17.

Signal 5B p2 to 5A p10 low.

Red outline on maze. Cyan monster is red, yellow is pink. All blue eyes.

3B p7 short to p8.

No Dots, Red Ms pac, blue monsters, no outline around maze.

White horizontal bars thru entire maze

Character ROM databus outputs CD0 thru CD7 are high.

5B,5C p3,4,5,6

5E,5F

Blue maze, red outline. Red Ms pacman, yellow dots.

3A,3B p2 low.

3B p4 low.

3A p2 short to p3,6,8.

All characters stuck on bottom of screen below credit.

WORKING

MS PACMAN

M(Black, Red, Black, Blue)

No Ms pacman, "Ms pac-man" name is blue. Missing Midway name, and marquee border.

Signal from 4A p12 to 3A,3B p14 high.

Signal from 3B p12 to 7F p10 low.

M(Black, Red, Black, Blue)

No Ms Pacman.

M(Red, Pink, Red, Pink)

All monster eyes are blue with no pupil.

2B bad, removed, shorted p15 & 16, or p7 high.

Signal from 3A p7 to 2B p15 high.

Signal from 3D p8 & 3B p6 is low.

M(cyan,yellow,cyan,yellow)

Ms Pacman is a dull pea green. All monster eyes white with no pupils.

M(yellow, blue, green, gray)

Yellow Ms pacman bow and lipstick.

M(pink, pink, orange, orange)

Blue Ms Pacman.

Signal from 3D p11 and 3A & 3B p10 is high.

M(yellow, blue, gray, cyan)

Yellow midway name, bottom of midway logo is yellow. Yellow outline around maze.

Signal from 4A p9 to 3A,3B p2 high.

M(black, yellow, black, blue)

No Ms Pacman.

2D bad or removed.

M(cyan, red, cyan, red)

Ms pacman grey, Midway logo blue & cyan. Blue eyes with no pupils. Marquee is blue.

Signal from 4A p10 to 3A,3B p5 high.

M(red, pink, cyan, orange)

Red Ms Pacman, Monster eyes white, yellow pupils.

2A bad, removed, or p7 high.

Signal from 3A p4 to 2A p15 high or shorted to 2A P16.

3D pin 1 is low.

M(red, red, cyan, cyan)

Ms Pacman’s blue center in ribbon is gone. Monsters have cyan eyes with yellow pupils.

2C bad, removed, shorted p15 to p16, or p7 is high.

Signal from 3A p9 to 2C p15 high.

Signal from 2C p7 to 3D p6 high.

3A p9 short to p16.

M(black, red, black, blue)

No Ms Pacman.

M(black, black, cyan, orange)

No Ms Pacman.

3B p1 short to p6.

M(black, black, black, black)

No Characters, No marquee, No midway name, No red border around maze, Dots are half width.

M(red, pink, red, pink)

Red Ms Pacman. White eyes, yellow pupils. Top of midway logo is pink.

3A p2 short to p5.

M(black, black, lines, lines)

Red maze outline. Blue dots. Vertical black lines thru cyan and yellow monsters. Red and pink monsters almost all black. No Ms Pacman.

3B p1 short to p7.

M(black, black, black, black)

All Eyes white. Ms pacman missing red bow.

3B p1 short to p3.

M(Red, Pink, Black, White) Monsters. Red Ms pac. Pupils orange, orange top, red on bottom of Midway logo.

Void of Blue. Top of Midway logo is black. All white including dots are yellow.

This is most likely caused by your monitor. If you have a known good monitor then:

Characters are blocks.

Void of Red. Bottom of Midway logo is black. Missing marquee and red monster.

This is most likely caused by your monitor. If you have a known good monitor then:

Void of Green. Red Ms Pacman, cyan is blue, yellow is red.

This is most likely caused by your monitor. If you have a known good monitor then:

Ms pac is flapping. Midway logo is a chopped up monster. Marquee is distorted.

M(Yellow, Pink, Red, Blue) Monsters. Ms pacman is Grey with yellow bow. Blue maze, yellow outline. Yellow game over, marquee, Midway copyright.

Graphics look like Egyptian Hieroglyphics.

Monsters are diced, chopped in quarters and re-assembled wrong.

6 Screens, no maze

Fliped words and graphics, not monsters.

4E p2,11 high = upside down.

4 Screens

3 Screens

Double characters

.

2F p10,13 high.

2 Screens, characters move quickly.

2S p12,13,14 low

3N p 9 low

2R p 12,13,14 high

2 Screens, score & credit vertical. Vertical lines for maze.

Score & Credit also displayed vertically on left and right side of the screen.

Sync Output on Oscilloscope

Should be constant