Coleco Pac-Man Mini-Arcade Troubleshooting
The general symptom list and procedures for Coleco's VFD Mini-Arcades are in Coleco Mini-Arcade Troubleshooting, written largely from repairs to Pac-Man boards. The notes below apply to the Coleco Pac-Man Mini-Arcade in particular: what a working game does, which grid or transistor a symptom points to on the Pac-Man board, and the Pac-Man behaviours that are not faults. Opening the game is in Coleco Pac-Man Mini-Arcade Maintenance and work on the display in Coleco Pac-Man Mini-Arcade VFD Repair.
What a working Pac-Man does
[edit | edit source]- Fit four fresh C alkaline cells; Coleco warns that weak cells cause an erratic display or erratic play.[1]
- Move the Skill 1/Off/Skill 2 switch to Skill 1 or Skill 2. The display lights; Coleco's guide calls this the red grid that shows the power is on.[1] A game with the first-version program, HD38820A28, does not show the whole maze at this point. This is how it was made.[2]
- Push the left stick right for Pac-Man, left for Head to Head Pac-Man, up for Eat & Run or down for the demonstration. The right stick does not select a game.[2][1]
- In Pac-Man the opening song plays, then Pac-Man moves off to the left on his own until the left stick turns him.[1]
Symptoms on the Pac-Man board
[edit | edit source]| Symptom | Where to look on the Pac-Man | Procedure |
|---|---|---|
| Dead, no sound | Red (B+) and blue (B−) battery wires, the power switch, transistors T1 and T2 on the 75690 board | No power[3][4][5] |
| Sound but dark display | Transistors T1 and T2, the display transformer, the exhaust tip of the DM-34Z, the display pins at each end | Sound but no display[5] |
| One horizontal row of the maze missing | One of grids G1 to G9; G4 is the fourth row up from the bottom | Coleco Pac-Man Mini-Arcade VFD Repair[5] |
| Part of the score area missing | One of the two score grids | Coleco Pac-Man Mini-Arcade VFD Repair[5] |
| A vertical band slightly dimmer than the rest | One of the eight filaments broken | Not repairable; the tube has to be replaced[5] |
| Game will not start from the right stick | Normal: only the left stick selects a game | None[1] |
| Right-hand player cannot move in Head to Head | Leaf switches or stick parts on the right-hand side | Swap the stick parts between the sides to locate the fault[6] |
| Pac-Man moves without the stick being touched | A stuck leaf switch under the left stick | Free or replace the leaf[4] |
| Sound very quiet | Speaker cone off the piezo buzzer in the base | Refit the cone and its ring[3] |
Transistors and the display supply
[edit | edit source]The 75690 board has two transistors in its power section: T1, a small three-legged type, and T2, a tabbed power type.[5] On the Rev. E board they are in different places and one of them is red.[7] Rik Morgan's experience is that these transistors fail after power is connected the wrong way round, that a failed one can get hot within seconds of switching on, and that both should be tested or replaced together.[5] A KLOV member whose Pac-Man had lost its switching transistor, the one that works with the display transformer, fitted a TIP41C NPN power transistor in its place and the game worked again.[8]
Display rows and grids
[edit | edit source]The DM-34Z has eleven grids. Nine cover the rows of the maze, one each, and two cover the score area; the board silkscreen labels them G1 to G11.[5] A whole row missing therefore points to one grid line. The Handheld Museum's Pac-Man lost its fourth row because the track from grid G4 to the microcontroller had corroded through.[5] MAME's driver shows the microcontroller driving the grids from its D5 to D15 outputs, and also uses D13 to D15 to read the skill setting and the two sticks.[2]
Things that are not faults
[edit | edit source]- Loud sound with no volume control.[9]
- No best score in Head to Head or Eat & Run; Pac-Man keeps its best score only until the power is switched off.[1]
- An incomplete maze at switch-on on the HD38820A28 version.[2]
- A dark or silvery patch about half an inch across inside the display glass, and a faint whine from the display transformer.[5]
Related pages
[edit | edit source]- Coleco Pac-Man Mini-Arcade
- Coleco Mini-Arcade Troubleshooting
- Coleco Pac-Man Mini-Arcade Maintenance
- Coleco Pac-Man Mini-Arcade VFD Repair
- Coleco Ms. Pac-Man Mini-Arcade Troubleshooting
References
[edit | edit source]- ↑ 1.0 1.1 1.2 1.3 1.4 1.5 Coleco Industries, Pac-Man Instructions and Game Rules, guide no. 76879A, model no. 2390, © 1981: cover (model number, four C cells, two skill levels, one or two players); p. 2 (the three games, controls and features); p. 3 (batteries, Perma Power battery eliminator/AC adaptor #2298, weak batteries, demonstration mode and the red grid shown at switch-on); pp. 4 to 6 (Pac-Man play, display key and scoring); pp. 7 to 9 (Head to Head Pac-Man and Eat & Run); p. 10 (special information and care); p. 11 (warranty and service policy). Hosted as File:Coleco Pac-Man Mini-Arcade Instructions 76879A.pdf.
- ↑ 2.0 2.1 2.2 2.3 MAME source,
src/mame/handheld/hh_hmcs40.cpp, driver notes for Coleco Pac-Man (cpacman,cpacmanr1): PCB label "Coleco 75690", Hitachi HD38820A28/A29 in a flat package, 1-bit sound, cyan/red Futaba DM-34Z 2A display, colour overlay, game selection with the player 1 stick, the Japanese release as Gakken's Super Puck Monster, and the note that the first version does not show the whole maze at power-on; the chip table at the head of the file. github.com/mamedev/mame. - ↑ 3.0 3.1 Rik Morgan, Handheld Museum, "Coleco Game Repair (Pac Man, Ms. Pac Man, Donkey Kong, Frogger & Galaxian)", page 1: teardown of a Pac-Man; the other Coleco games of the same design are almost identical apart from their controls; the two hood screws under the control panel sticker, the five base screws, the speaker cone over a piezo buzzer, and the red (positive) and blue (negative) battery wires. handheldmuseum.com. Owner's repair report.
- ↑ 4.0 4.1 Rik Morgan, Handheld Museum, "Coleco Game Repair", page 2: the four wires to the main board (B+, B− and two PZ speaker connections), the three board screws, the joystick parts, worn or stuck leaf switches, and the two lens screws. handheldmuseum.com. Owner's repair report.
- ↑ 5.00 5.01 5.02 5.03 5.04 5.05 5.06 5.07 5.08 5.09 Rik Morgan, Handheld Museum, "Coleco Game Repair", page 3: no-power faults (supply wires, power switch, the two transistors and reverse polarity), no picture with sound (broken glass, the exhaust tip, the display supply transformer, bad joints at the display), partial display faults, the eight filaments, the nine playfield grids and two score grids, and the repair of a corroded grid trace; with photographs of the 75690 board's power section (transformer, transistors T1 and T2, zener diodes ZD1 and ZD2, two electrolytic capacitors). handheldmuseum.com. Owner's repair report.
- ↑ AtariAge forums, "Handheld/Tabletop repair options", thread 158637: worn joysticks on the Coleco Pac-Man, the thin metal joystick contacts, swapping the player 1 and player 2 parts to locate a fault, and microswitches as a replacement. forums.atariage.com. Community repair discussion.
- ↑ Rik Morgan, Handheld Museum, "Coleco Game Repair", board-variation page: a second Pac-Man board marked Rev. E, with a round black display transformer and relocated transistors. handheldmuseum.com.
- ↑ KLOV forums, "PACMAN Coleco repair : component information", thread 199101, August to September 2011: a Pac-Man whose switching transistor was missing; the owner identified it as the transistor that works with the display transformer and fitted a TIP41C NPN transistor, after which the game worked. forums.arcade-museum.com. Community repair report.
- ↑ Robert Maloney, "Retro-Gaming with Coleco", HotHardware, 30 September 2004, pages 2 and 3: the Perma Power or four C cells, the inside of an opened unit, the mottling of the decals on the author's Pac-Man where the glue has seeped through ("a common issue with these units"), the Pac-Man's loud sound with no volume control, and the differences of the Ms. Pac-Man (maze variations, the moving bonus fruit, the character graphics). hothardware.com.