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Grandstand Tabletop Maintenance

From RetroTechCollection
Astro wars front view
A Grandstand Astro Wars on its box at Wardown Park Museum, Luton. The box carries the Grandstand model number 11183.

Care, cleaning and opening of the eleven battery-powered tabletop games with a vacuum fluorescent display (VFD) that Grandstand sold in the UK from 1980 to 1984: Invader From Space, Astro Wars, Munchman, Tron, The Big Game Soccer, Cosmic Invader, Caveman, Scramble, Crazy Monster, Firefox F-7 and Star Force.[1][2] Grandstand was the brand of Adam Imports of Harrogate, which did not make them: Epoch and Tomy built them in Japan and VTech in Taiwan, and the same games were sold under other names in other countries.[3][4][5][6]

No Grandstand service manual, service note or schematic has been found for any of the eleven. The instruction leaflets cover batteries, the mains adaptor and care. Owners have since traced parts of the Epoch power circuit on the Astro Wars, and that work is the main repair evidence on these pages. Fault-finding is on Grandstand Tabletop Troubleshooting; the display and the circuit that powers it are on Grandstand Tabletop VFD Repair. Each guide ends with a section for each title.

The eleven games

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Grandstand VFD tabletop games: original maker, main parts and power
Grandstand title Original maker and name Microcontroller Display Cells Adaptor, as printed by the maker
Invader From Space Epoch, Invader From Space NEC μPD552C, labelled D552C 054 NEC FIP9AM18T, cyan 4 × AA 6 V DC, 200 mA; polarity not printed (Epoch)
Astro Wars Epoch, Galaxy II NEC μPD553C, labelled D553C 153 NEC FIP10xM20T, cyan and red 4 × C Grandstand Universal Mains Adaptor set to negative; 6 V DC, 250-300 mA, centre negative (Epoch)
Munchman Tomy, Pac Man / Puck Man NEC μPD553C, labelled D553C 160 NEC FIP8AM18T, cyan, red and green 4 × C 7.5 V DC, 200 mA, 2.1 mm plug, centre negative (Tomy)
Tron Tomy, Tron Hitachi HD38800A88 NEC FIP10AM24T, cyan, red and green 4 × C 7.5 V DC, 200 mA, 2.1 mm plug, centre negative (Tomy)
The Big Game Soccer Epoch, Exciting Soccer Game Not identified VFD, part not identified 4 × AA Not found
Cosmic Invader VTech, Invaders / Sonic Invader Hitachi HD38750A45 Futaba DM-26Z 1G, cyan and red 4 × AA Not found
Caveman Tomy, Caveman NEC μPD553C, labelled D553C 209 NEC FIP8AM20T, cyan, red and green 4 × C 7.5 V DC, 200 mA, centre negative (Tomy)
Scramble Epoch, Astro Command NEC μPD553C, labelled D553C 202 NEC FIP9AM20T, cyan and red 4 × C No leaflet found
Crazy Monster Epoch, Zig-Zag Monster Not identified VFD, part not identified 4 × C Grandstand Universal Mains Adaptor set to negative
Firefox F-7 Epoch, Astro Thunder 7 Not identified NEC FIP-series VFD, number not legible 4 × C Grandstand Universal Mains Adaptor set to negative; 6 V, centre negative (Radio Shack)
Star Force Epoch, Star Force NEC D7528C-016 (Handheld Museum) Multicoloured VFD 4 × C Grandstand Universal Mains Adaptor set to negative

Makers, microcontrollers and display parts from the MAME drivers,[3][4] except Star Force (Handheld Museum[2]) and Firefox F-7 (a photograph of the board[7]). Cells and adaptors from the leaflets: Grandstand's for Astro Wars, Firefox F-7, Crazy Monster and Star Force;[5][6][8][9] the original makers' for the others;[10][11][12][13][14][15] the Handheld Museum for the cell types where no leaflet was found.[16][17][18]

Construction by maker

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Epoch

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Seven of the eleven are Epoch designs: Invader From Space, Astro Wars, The Big Game Soccer, Scramble, Crazy Monster, Firefox F-7 and Star Force. Where the microcontroller has been identified on the older titles it is an NEC μPD552 or μPD553. NEC's data sheet describes both as PMOS chips that run from a single −10 V supply and can drive a VFD directly, with 27 output lines that can be pulled to −35 V.[19][3] The game therefore has to make negative supplies from its four cells: owners have measured about −10 V at the microcontroller and −39 V for the display on Astro Wars.[20] The Astro Wars makes them with a small transformer driven by a power transistor, S02, a D882 NPN type; S03, S04 and S05 are smaller transistors, which one repairer replaced with 2SA1175 PNP types.[21][22] The Astro Command, the Epoch version of Scramble, has D882 and C2785 transistors in the same place.[23] The boards use the prefix S for transistors and diodes alike.

The games are built from a main board carrying the display and microcontroller, and a separate control board for the buttons. The joystick on Astro Wars sits on a small board of its own. On Astro Wars the main board stands upright in the hood with the display on it; on Firefox F-7 the display stands on a bracket above the main board.[7] Power from the battery box and the DC socket runs through the power switch on the control board and reaches the main board through a multi-way cable, so a broken wire in that cable leaves the game dead.[24][23] The board numbers are 36010 (A/B) on Invader From Space, 19096 and 96062 on Astro Wars, and 96111 and 96112 on Scramble; the Astro Wars numbers are confirmed by a photograph of the opened game.[3][7]

Astro Wars, Scramble, Firefox F-7 and Star Force share a battery cover. The designer of a 3D-printed replacement lists all four with their Epoch and Radio Shack versions, and Wikipedia's list of games with the same battery compartment agrees.[25][26]

Tomy

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Munchman, Tron and Caveman are Tomy games. Munchman and Caveman use NEC μPD553 microcontrollers, labelled D553C 160 and D553C 209; Tron uses a Hitachi HD38800A88. The boards are marked TN-08 2E108E01 (Munchman), TN-12 2E114E03 (Caveman) and THN-02 2E114E07 (Tron).[3][4] The cases differ: Munchman is round and bright yellow, Tron is smoked clear plastic that shows the inside, and Caveman was made in gold and red or white and orange.[3][27][28] The Grandstand Munchman is marked Tomy on the base.[29] Tomy's leaflets ask for a 7.5 V adaptor rather than Epoch's 6 V.[12][13][14] No description of a Tomy power section has been found.

VTech

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Cosmic Invader is VTech's Invaders, also sold as Sonic Invader, made in Taiwan around a Hitachi HD38750A45 and a Futaba DM-26Z 1G display, and run from four AA cells.[4][18] Nothing about its construction or repair has been published.

Before you start

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  • No schematic exists for any of these games. Photograph each stage as you take a game apart, and keep the screws for each part together.
  • A second, working game of the same title is the most useful repair tool. The Astro Wars and Astro Command repairs that have been written up were solved, or narrowed down, by comparing voltages with a working unit and swapping parts between the two.[21][23][30]
  • Keep the small parts of any game you scrap: rubber button contacts, springs and speakers fit other games of the same family.[21] One repairer cured an Astro Wars with two diodes taken from a scrap Grandstand Scramble.[30]
  • Take the cells out before you open the case.

Batteries and contacts

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The Grandstand leaflets ask for four Duracell MN1400 (C size) alkaline cells, say that the game will not work properly on weak batteries, and tell the owner to check or replace the batteries if play or the display becomes erratic.[5][6][9] Tomy's leaflets say the display goes dark and shows incorrect action.[12] Three titles take AA cells instead: Invader From Space, The Big Game Soccer and Cosmic Invader.[10][17][18] One collector's guide says D cells for Astro Wars and Scramble; the leaflets and the Handheld Museum say C.[31][16]

  • Leaking cells are the commonest damage. Games stored in lofts with the batteries in have corroded terminals and electrolyte on the board.[31] Radio Shack's manual warns that "even leakproof type batteries can leak damaging chemicals".[15] Clean and neutralise the residue as described on Battery Explosion, Capacitor or Corrosion Damage, and look along the tracks near the battery leads for green or broken copper.
  • Rusty contacts can be cleaned and, if pitted, filed back to bright metal, as was done on an Astro Command.[23]
  • Take the cells out when the game is put away. Every leaflet says so.[5][12]
  • Missing battery covers: a 3D-printable cover fits the Epoch family (Astro Wars, Scramble, Firefox F-7, Star Force), and another fits Invader From Space. Both are published under CC BY 4.0.[25][32]

The DC socket and adaptors

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All the Grandstand leaflets name the Grandstand Universal Mains Adaptor and tell the owner to set its polarity switch to negative, but none gives a voltage.[5][6][8][9] The voltage comes from the original makers, and differs between them:

Adaptor requirements printed by the original makers
Family Voltage and current Polarity Plug Source
Epoch (Galaxy II, the Astro Wars original) 6 V DC, 250-300 mA Centre negative Not stated Epoch leaflet[11]
Epoch (Invader From Space) 6 V DC, 200 mA Not printed Not stated Epoch leaflet[10]
Epoch (Astro Thunder, the Firefox F-7 original) 6 V range Centre tip negative Not stated Radio Shack manual[15]
Tomy (Pac Man, Tron, Caveman) 7.5 V DC, 200 mA Centre negative 2.1 mm coaxial (Pac Man and Tron) Tomy leaflets[12][13][14]
  • Centre negative is the reverse of most modern adaptors. One Astro Wars repairer notes that the outer contact of the plug is positive and that the game has no diode to protect it from reversed polarity; he fitted one.[22] The Handheld Museum's administrator calls a wrong adaptor the commonest damage he sees in VFD games, usually a blown transistor.[21] Two Astro Wars owners traced their games' failure to the wrong adaptor having been plugged in.[20][33]
  • Use a regulated supply at the voltage printed for that maker, with the centre negative, and measure the plug with a multimeter before connecting it. The Grandstand Universal Mains Adaptor gives 6-9 V and has a switch for polarity and off; the Handheld Museum notes that 100-200 mA adaptors run these games.[34] It is a 40-year-old mains device: check the cable and the case before using one. See Grandstand Universal Mains Adaptor.
  • An Astro Wars runs from 5 V, but the display is dimmer than at 6 V.[22]
  • On Munchman a damaged power socket can lock the game into running only from the adaptor: the socket carries the contact that connects the cells when no plug is inserted.[35] Test every game on batteries alone as well as on an adaptor.

Opening the case

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No step-by-step disassembly guide has been published for any of these games, so the screw positions are not listed here. What the photographs and repair logs show:

  • On the Epoch games the controls are on their own board, joined to the main board by wires or a ribbon cable. On Astro Wars the main board, with the display, stands in the hood, and the control board and the joystick board sit in the base in front of it.[7][24]
  • Lift boards out without straining the wires between them. On an Astro Command the ribbon cable from the control board frayed and broke after the main board had been turned over several times during repair.[23]
  • On The Big Game Soccer the battery holder runs along the top of the base, the DC socket is at the top right, and each player has a control board at the side.[7]
  • The display is a glass tube. Do not lever against it, and keep tools away from the glass tip on the tube. See Grandstand Tabletop VFD Repair.[26]

Controls

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  • The leaflets ask for the joystick to be moved gently and the fire button not to be pressed hard.[5][6]
  • Clean switch and button contacts with isopropyl alcohol.[26] One buying guide suggests WD-40; it leaves an oily film and is not a contact cleaner.[31]
  • The Firefox F-7 control board has round contact pads under the buttons, and the buttons of these games use rubber contacts.[7][21] Clean the pads and the rubber contacts with alcohol; do not scrape them.
  • A game that seems silent may only have its sound turned off: Firefox F-7 has left and right speaker switches, and Star Force has a sound button.[6][9]

Display window, magnifier and labels

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  • Astro Wars views its display through a magnifier in the hood.[5] The Astro Command has a magnifying lens behind the window and a printed transparent backdrop.[23]
  • Windows scratch and sometimes crack. Small scratches can be polished out; cracks cannot be repaired.[35]
  • Title stickers fade, peel or go missing.[35]
  • Wipe the case with a damp cloth. Radio Shack's manual warns against harsh chemicals, solvents and strong detergents.[15]

Storage

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  • Cells out, game dry, out of the sun and away from heat. The Grandstand leaflets warn against sun and wet; Radio Shack's manual adds heat, dust and drops.[5][15]
  • Switch off after use. The leaflets say so to save the batteries.[5]

Invader From Space

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Epoch's Invader From Space, made in Japan; the V&A dates the Grandstand version 1980 and records its "blue fluorescent display".[1] The board is marked 36010 (A/B); the microcontroller is an NEC μPD552C labelled D552C 054; the display is a single-colour cyan NEC FIP9AM18T under a coloured overlay.[3] It takes four AA cells, not C. Epoch's leaflet asks for a 6 V DC, 200 mA adaptor and prints no polarity; no Grandstand leaflet has been found.[10][36] A 3D-printable battery cover has been published for this title.[32]

Astro Wars

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Epoch's Galaxy II, made in Japan.[5][11] Main board 19096 and control board 96062; NEC μPD553C labelled D553C 153; NEC FIP10xM20T display in cyan and red, made in at least two revisions with different graphics (rev B no. 1-8 and rev D no. 2-21).[3][7] Four C cells. Grandstand's leaflet says to set the Universal Mains Adaptor to negative; Epoch's asks for 6 V DC at 250-300 mA, centre negative.[5][11] The battery cover is the shared Epoch one.[25]

There are versions with white and with red "Astro Wars" lettering.[37] One repairer found his red-lettered game had a slightly different board revision from his white-lettered one, and another found a board marked "v3" with a second diode, S011, in series with S06 in the display supply.[21][30] Note the board revision before ordering parts. The power transistor and S06 faults are on Grandstand Tabletop Troubleshooting#Astro Wars.

Munchman

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Tomy's Pac Man, sold in Japan as Puck Man; the Grandstand version is marked Tomy on the base.[29] Board TN-08 2E108E01; NEC μPD553C labelled D553C 160; NEC FIP8AM18T display in cyan, red and green; round yellow case.[3][38] Four direction buttons, an on/off switch and an AMA/PRO switch.[38] Four C cells; Tomy's US leaflet asks for a 7.5 V DC, 200 mA adaptor with a 2.1 mm plug, centre negative. No Grandstand leaflet has been found.[12]

A collector's guide to Munchman gives three things to check: the window (scratches polish out, cracks do not), the title sticker above the screen, and that the game runs on batteries alone, because a damaged power socket can lock it into running only from the adaptor.[35]

Tron

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Tomy's Tron (Tomy model 7601; Grandstand model 11266).[27] Board THN-02 2E114E07; Hitachi HD38800A88 microcontroller; NEC FIP10AM24T display in cyan, red and green.[4] The smoked clear case shows the inside.[27] Four C alkaline cells; Tomy's leaflet asks for 7.5 V DC, 200 mA, with a 2.1 mm plug, centre negative.[13] MAME's driver does not mention a Grandstand release; the Grandstand-branded unit and box are recorded by the Handheld Museum.[27]

The Big Game Soccer

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Epoch's Exciting Soccer Game, sold by Grandstand as Kevin Keegan's The Big Game Soccer; four AA cells.[17] It is not in MAME, and the microcontroller has not been identified. A photograph of the opened game shows a glass VFD tube on the main board, a battery holder along the top, the DC socket at the top right, and a separate control board for each player.[7] The Centre for Computing History describes it as an LED game; the photograph shows a VFD.[39] No adaptor rating has been found.

Cosmic Invader

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VTech's Invaders, also sold by VTech as Sonic Invader and by Prinztronic as Galactic Invaders; made in Taiwan.[4][18] Hitachi HD38750A45 microcontroller; Futaba DM-26Z 1G display in cyan and red; four AA cells. No leaflet, adaptor rating or teardown has been found.

Caveman

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Tomy's Caveman (Tomy model 7613), sold by Grandstand as Cave Man - Jr. Caveman vs Dinosaur.[3][28] Board TN-12 2E114E03; NEC μPD553C labelled D553C 209; NEC FIP8AM20T display in cyan, red and green.[3] Found in gold and red and in white and orange cases.[28] Four C cells; Tomy's leaflet asks for 7.5 V DC, 200 mA, centre negative.[14]

Scramble

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Epoch's Astro Command (Epoch model 8230), also sold by Tandy.[3][16] Boards 96111 and 96112; NEC μPD553C labelled D553C 202; NEC FIP9AM20T display in cyan and red. Four C cells.[16] No Grandstand or Epoch leaflet for this game has been found, so its adaptor rating is not known; the other Grandstand leaflets for Epoch games all set the adaptor to negative. The battery cover is the shared Epoch one.[25]

An owner who repaired an Astro Command found that the battery current passes through the control board and a ribbon cable to the main board, and that the cable frays if the board is turned over repeatedly.[23] The word "Scramble" on the case is found both unpainted and painted red.[16]

Crazy Monster

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Epoch's Zig-Zag Monster (Epoch model 36270, 1983).[40] The microcontroller and display part have not been identified; it is not in MAME. Four Duracell MN1400 (C) cells; the Grandstand leaflet sets the Universal Mains Adaptor to negative.[8]

Firefox F-7

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Epoch's Astro Thunder 7, also sold as Epoch Galaga X6 and Radio Shack Astro Thunder.[41] Made in Japan; the V&A dates it 1983.[42] The display stands on a bracket above the main board; it carries an NEC FIP part number that cannot be read in the only published photograph, and the microcontroller has not been identified.[7] Four C cells; Grandstand's leaflet sets the Universal Mains Adaptor to negative, and Radio Shack's manual for the same game asks for 6 V, centre negative.[6][15] The battery cover is the shared Epoch one.[25]

Firefox F-7 has two speakers with a switch for each.[6] Radio Shack's manual describes one switch as turning the music off and the other the sound effects.[15] Check both before treating the game as silent.

Star Force

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Epoch's Star Force, 1984. The Handheld Museum reads the microcontroller as an NEC D7528C-016; it is not in MAME.[2] Four Duracell MN1400 (C) cells; the Grandstand leaflet sets the Universal Mains Adaptor to negative and its drawing shows the adaptor socket on the right-hand side of the case.[9] The battery cover is the shared Epoch one.[25] The sound button turns the sound effects off; check it before chasing a sound fault.[9]

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References

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  1. ↑ 1.0 1.1 Victoria and Albert Museum, O27497, "invader from space", "Grandstand electronic game" (retrieved 2026-10-18): table game, 1980, made in Japan, "battery operated, hand held; with blue fluorescent display".
  2. ↑ 2.0 2.1 2.2 Handheld Museum, "Grandstand Star Force" (retrieved 2026-10-18): 1984, VFD, four C cells, model 11055, "CPU: NEC D7528C-016"; Grandstand release of Epoch's Star Force. Also "Epoch Star Force": 1984, VFD, four C cells.
  3. ↑ 3.00 3.01 3.02 3.03 3.04 3.05 3.06 3.07 3.08 3.09 3.10 3.11 MAME source, hh_ucom4.cpp at commit d404316 (retrieved 2026-10-18). Driver notes, written from real boards, for Epoch Invader From Space (PCB 36010(A/B); NEC uCOM-44 MCU labelled D552C 054; cyan VFD NEC FIP9AM18T; UK release by Grandstand), Epoch Galaxy II (PCB 19096/96062; uCOM-43 labelled D553C 153; cyan and red VFD NEC FIP10xM20T, rev B no. 1-8 and rev D no. 2-21 with different graphics; UK release by Grandstand as Astro Wars), Epoch Astro Command (PCB 96111/96112; D553C 202; NEC FIP9AM20T no. 42-42; UK release by Grandstand as Scramble), Tomy Pac-Man (PCB TN-08 2E108E01; D553C 160; NEC FIP8AM18T no. 2-21; round yellow case; UK release by Grandstand as Munchman) and Tomy Caveman (PCB TN-12 2E114E03; D553C 209; NEC FIP8AM20T no. 2-42; UK release by Grandstand). The file header explains the NEC FIP part numbers (the first figure is the number of grids) and notes that VFD colours fade after decades.
  4. ↑ 4.0 4.1 4.2 4.3 4.4 4.5 MAME source, hh_hmcs40.cpp at commit d404316 (retrieved 2026-10-18). Driver notes for Tomy Tron (made in Japan; PCB THN-02 2E114E07; Hitachi HD38800A88; cyan, red and green VFD NEC FIP10AM24T no. 2-8 1) and VTech Invaders (made in Taiwan; Hitachi HD38750A45; cyan and red VFD Futaba DM-26Z 1G; UK releases as Grandstand Cosmic Invader and Prinztronic Galactic Invaders).
  5. ↑ 5.00 5.01 5.02 5.03 5.04 5.05 5.06 5.07 5.08 5.09 5.10 Grandstand, Astro Wars instruction leaflet (Adam Leisure Group PLC, Harrogate; © 1981 Epoch, made in Japan), hosted here as File:Grandstand Astro Wars Instructions.pdf (PDF page numbers): p. 2, controls, skill levels and the batteries box (four Duracell MN1400; Grandstand Universal Mains Adaptor with the polarity switch set to negative; the game will not work properly on weak batteries; check batteries if play or display is erratic; remove batteries for long periods); p. 3, "move the Joy Stick gently. Do not press hard on the Fire Button ... Do not leave in the sun or allow it to get wet", and a perfect score of 10,000; pp. 4-5, the four phases; p. 6, imprint.
  6. ↑ 6.0 6.1 6.2 6.3 6.4 6.5 6.6 6.7 Grandstand, Firefox F-7 instruction booklet (Adam Imports Ltd, Ripon Way, Harrogate; © 1983; made in Japan), hosted here as File:Grandstand Firefox F-7 Instructions.pdf (PDF page numbers): p. 1, control drawing (left and right speaker switches) and batteries box (four Duracell MN1400; Universal Mains Adaptor on negative polarity; weak-battery warning; care note); pp. 2-4, controls, three skill levels, high and low speed and the display; pp. 5-7, the five phases of combat and the sixth against the enemy base; p. 8, scoring and a perfect game of 1,000 points.
  7. ↑ 7.0 7.1 7.2 7.3 7.4 7.5 7.6 7.7 7.8 Handheld Museum, "Guts" (retrieved 2026-10-18): photographs of opened Grandstand Astro Wars (main board 19096 standing in the hood with the display; control board 96062 marked START, SELECT and FIRE; joystick on its own small board), The Big Game Soccer (main board in the centre with the display; battery holder along the top; DC socket at the top right; a control board each side) and Firefox F-7 (display on a bracket above the main board, with "FIP" and an illegible number in the silkscreen beside it; two chips on the main board, neither legible; control board with round contact pads below).
  8. ↑ 8.0 8.1 8.2 Grandstand, Crazy Monster instruction leaflet (Adam Imports Ltd, Harrogate; made in Japan), hosted here as File:Grandstand Crazy Monster Instructions.pdf: p. 1, batteries box (four Duracell MN1400; Universal Mains Adaptor set to negative polarity; weak-battery warning).
  9. ↑ 9.0 9.1 9.2 9.3 9.4 9.5 Grandstand, Star Force instruction booklet (distributed by Adam Imports Ltd, Ripon Way, Harrogate; printed in Japan; no date printed), hosted here as File:Grandstand Star Force Instructions.pdf (PDF page numbers): p. 1, control drawing with the adaptor plug entering a socket on the right-hand side, and batteries box (four Duracell MN1400; Universal Mains Adaptor on negative polarity; weak-battery warning; care note); p. 2, sound button, four skill levels with 9, 7, 7 and 5 lives, seven phases and the phase select button; p. 3, joystick and firing button; pp. 4-6, the phases and scoring; p. 7, a perfect score of 3,000.
  10. ↑ 10.0 10.1 10.2 10.3 Epoch, Invader From Space instruction leaflet (© 1980 Epoch; made in Japan), hosted here as File:Epoch Invader From Space Instructions.pdf: p. 3, four AA cells, or an adapter of 6 V DC, 200 mA (no polarity printed); weak-battery warning.
  11. ↑ 11.0 11.1 11.2 11.3 Epoch, Galaxy II instruction leaflet (Epoch Corporation, Englewood, New Jersey; © 1981 Epoch Company Ltd, Tokyo; made in Japan), hosted here as File:Epoch Galaxy II Instructions.pdf: p. 2, four C cells, or an adapter of 6 V DC, 250-300 mA, with a polarity symbol showing the centre pin negative.
  12. ↑ 12.0 12.1 12.2 12.3 12.4 12.5 Tomy, Pac Man instruction sheet (US edition, Tomy Corporation, Carson, California), hosted here as File:Tomy Pac Man Instructions.pdf: p. 1, four C cells; AC adapter 7.5 V DC 200 mA with a 2.1 mm coaxial plug, tip (centre) negative; AMA and PRO settings; "If the batteries become weak the display screen will become dark and show incorrect action."
  13. ↑ 13.0 13.1 13.2 13.3 Tomy, Tron instruction leaflet (© 1982 Tomy Corp., Carson, California), hosted here as File:Tomy Tron Instructions.pdf: p. 2, four C alkaline cells; AC adapter 7.5 V DC 200 mA, 2.1 mm coaxial plug, tip (centre) negative; p. 6, care, and a dark display with incorrect action on weak batteries.
  14. ↑ 14.0 14.1 14.2 14.3 Tomy, Caveman instruction leaflet, hosted here as File:Tomy Caveman Instructions.pdf: p. 1, four 1.5 V "baby" (C) cells; AC adaptor 7.5 V DC 200 mA, tip (centre) negative; p. 4, a dark display with incorrect action on weak batteries.
  15. ↑ 15.0 15.1 15.2 15.3 15.4 15.5 15.6 Radio Shack, Astro Thunder owner's manual (custom manufactured for Radio Shack; printed in Japan), hosted here as File:Radio Shack Astro Thunder Manual.pdf. The same game as the Firefox F-7. p. 1: four C cells, or Radio Shack's 273-1650 adapter on its 6 V range with the centre tip set negative (270-7001 for 240 V in the UK); check the batteries if the game malfunctions or the display is erratic; "Even leakproof type batteries can leak damaging chemicals, which will ruin your unit permanently". p. 2: left and right sound switches. p. 7: maintenance (keep dry, no heat, no harsh chemicals, fresh alkaline cells).
  16. ↑ 16.0 16.1 16.2 16.3 16.4 Handheld Museum, "Grandstand Scramble" (retrieved 2026-10-18): 1982, VFD, four C cells; licensed from Epoch (Astro Command); found with the word "Scramble" unpainted and painted red; maximum score 3,000. Also "Epoch Astro Command": 1982, VFD, four C cells, model 8230, also sold by Tandy.
  17. ↑ 17.0 17.1 17.2 Handheld Museum, "Grandstand The Big Game Soccer" and "Epoch Exciting Soccer Game" (retrieved 2026-10-18): 1981, VFD, four AA cells; licensed from Epoch; sold in the UK as Kevin Keegan's The Big Game Soccer.
  18. ↑ 18.0 18.1 18.2 18.3 Handheld Museum, "Grandstand Cosmic Invader" (retrieved 2026-10-18): 1981, VFD, four AA cells; identical to VTech's Sonic Invader; also sold by Prinztronic as Galactic Invaders.
  19. ↑ NEC Electronics USA, 1982 Microcomputer Catalog, data sheet "μPD552/μPD553 4-bit single chip microcomputers with vacuum fluorescent display drive capability", p. 165. Bitsavers copy on the Internet Archive. Both chips are PMOS parts in a 42-pin DIP running from a single −10 V supply; 27 of their I/O and output lines "are capable of being pulled to −35V in order to drive Vacuum Fluorescent Displays directly". The μPD553 has 2000 × 8 ROM and 96 × 4 RAM, the μPD552 1000 × 8 and 64 × 4.
  20. ↑ 20.0 20.1 All About Circuits forum, "Grandstand Astro Wars Game (Faulty) - help with component identification", February 2019 - January 2024 (retrieved 2026-10-18). The owner's own measurements and hand-drawn schematic (which he did not guarantee): 6 V in, about −10 V for the microcontroller and −39 V for the display; with a faulty S06 the D882 (S02) overheated and the game drew 1.5 A; a good S06 from another unit cured it; a 39 V zener did not; S06 is a glass diode with red and brown bands (another owner's has a single red band). Later posts: one member fixed the same fault with a 1N5275B zener; another fixed his, damaged in about 1985 by the wrong mains adaptor, by replacing S06.
  21. ↑ 21.0 21.1 21.2 21.3 21.4 21.5 Handheld Museum forum, "Astro wars / galaxy ii repair", December 2018 - February 2019 (retrieved 2026-10-18). A dead Astro Wars: the D882 power transistor ran hot, the supply fell to about 1.5 V and the game drew 1.5-1.7 A; a replacement D882 did the same; diode S06 read about 20 Ω both ways; with S06 removed the μPD553 received its −10 V and ran when the display was fed from a separate supply; S06 taken from a working unit cured it. Also the μPD553-to-VFD pin map (filament on VFD pins 1 and 30), an out-of-circuit test of the display, the transformer connections, and the note that a red-lettered unit had a slightly different board revision. The site's administrator (Rik) writes that the wrong AC adapter "will usually fry" a transistor, "the most frequent damage I've seen to VFD games", and advises keeping the rubber buttons, springs and speakers from scrapped games. Another member expected a healthy game to draw about 100 mA. The owner traced S06 to the transformer at one end and, through R07, to the piezo speaker at the other; with S06 removed the game made no sound. Measured with a basic oscilloscope he thought might be inaccurate: about 200 V peak to peak from the transformer at S06 and −39 V DC on its other side. Lower-voltage zeners tried in place of S06 (32 V, then 39 V) left the D882 or the zener overheating.
  22. ↑ 22.0 22.1 22.2 Andy van Stokkum, "Repairing an Astro Wars", codify.nz, 15 June 2019 (retrieved 2026-10-18). Repair log: S02 ran hot and was replaced; the game worked for about a month, then S02 failed again and S03 ran hot; finally replaced S06 (a 140 V zener; 2 W parts used where 500 mW would do), S03-S05 (2SA1175), S02 (D882) and all electrolytic capacitors. The adaptor plug is outer-positive and the game has no reverse-polarity diode; he added one. It runs from 5 V but the display is dimmer than at 6 V.
  23. ↑ 23.0 23.1 23.2 23.3 23.4 23.5 23.6 Handheld Museum forum, "EPOCH Astro Command - dead or dying", January-February 2016 (retrieved 2026-10-18). An Epoch Astro Command (the Epoch version of Grandstand Scramble): rusty battery contacts cleaned and filed; before failing it showed incorrect play and a rapidly flashing display; the Radio Shack version has almost the same parts; MCU D553C 202, transistors D882 and C2785; power from the batteries runs through the control board and a ribbon cable that frayed after the board was turned over repeatedly; unresolved. Rik (site administrator): the game plays and makes sounds without the display or its transformer; displays fade unevenly with heavy use; a broken filament wire leaves an area dim; he has never had a display fail unless the glass was broken.
  24. ↑ 24.0 24.1 bpharoah, "More Astro Wars!", 24 April 2023 (retrieved 2026-10-18). A dead Astro Wars: 6 V with negative polarity at the DC socket; the supply traced through a red wire to the power switch and through the control panel cable; the power transistor had a base-emitter short; a new transistor cured it.
  25. ↑ 25.0 25.1 25.2 25.3 25.4 25.5 YoxxxoY Jorge, "Battery cover Epoch electronic games", Thingiverse 3399673 (2019), archived on the Internet Archive (retrieved 2026-10-18). 3D-printable battery cover; the designer lists Astro Thunder, Astro Thunder 7, Firefox F-7, Astro Command, Astro Wars, Space Defender, Galaxy II, Star Force and Scramble. CC BY 4.0.
  26. ↑ 26.0 26.1 26.2 Wikipedia, "Astro Wars" (revision of 1 June 2025). Hardware section, without references: the D882 power transistor "is known to fail frequently", the S06 zener less often; the display has "a glass nipple which can easily be fractured"; isopropyl alcohol for contacts; the same battery compartment on Astro Thunder, Astro Thunder 7, Firefox F-7, Astro Command, Space Defender and Scramble. The article also calls the game "made in Great Britain", which the Grandstand leaflet contradicts.
  27. ↑ 27.0 27.1 27.2 27.3 Handheld Museum, "Grandstand Tron" and "Tomy Tron" (retrieved 2026-10-18): 1981, VFD, four C cells; Grandstand model 11266; Tomy model 7601; the case is smoked clear plastic that shows the inside.
  28. ↑ 28.0 28.1 28.2 Handheld Museum, "Grandstand Caveman" and "Tomy Caveman" (retrieved 2026-10-18): 1982, VFD, four C cells; Tomy model 7613; made by Tomy and licensed to Grandstand; also found in a white and orange case.
  29. ↑ 29.0 29.1 Handheld Museum, "Tomy Pac Man, Etc." (retrieved 2026-10-18): model TKY-7612, four C cells; the same game sold as Pac Man, Puck Man and Munchman, identical except for the name sticker and instructions; the Grandstand Munchman "says Tomy on the bottom".
  30. ↑ 30.0 30.1 30.2 Electro-Tech-Online forum, "Grandstand 'Astro Wars' / Epoch 'Galaxy II' Repair", January-February 2019, pages 1-2 (retrieved 2026-10-18; the opening posts were later deleted by their author). A repairer (retreotechrepair) fixed an Astro Wars with the same S06 fault: his working comparison unit, a "v3" board, had a second diode, S011, in series with S06, and he fitted an S06 and S011 taken from a scrap Grandstand Scramble; on the working unit he measured −39 V at pin 1 of R01 and R02 and −31.8 V and −32.8 V at display pins 1 and 2; with a stack of PP3 batteries he found S06 and S011 each break down at about 140-144 V.
  31. ↑ 31.0 31.1 31.2 Retro Games Now, "Astro Wars by Grandstand" (retrieved 2026-10-18). Collector's buying guide: games left in lofts with batteries in have corroded terminals and acid on the board; a display that fades "cannot be replaced"; repeats the D882 and S06 points; red-lettered version described online as the "launch" edition; recommended price about £30 in 1981, later about £23 in Argos catalogues. It says four D cells; the Grandstand leaflet says MN1400, which is the C size.
  32. ↑ 32.0 32.1 Mike Underwood, "Grandstand Invaders From Space Battery Cover", Thingiverse 4888078 (2021), archived on the Internet Archive (retrieved 2026-10-18). CC BY 4.0.
  33. ↑ All About Circuits forum, "Help with replacement part - Repairing old electronic game", August-October 2022 (retrieved 2026-10-18). Two Astro Wars: one cured by a new D882; the other, which had been given the wrong adapter, had the zener fault. The 1N5275B is a 140 V, 0.5 W zener; two 1N4760 68 V zeners in series were fitted instead and the game worked.
  34. ↑ Handheld Museum, "Grandstand Universal Mains Adapter" (retrieved 2026-10-18): model UGT, for 240 V; a switch selects the polarity or turns the output off; 6-9 V DC; "100-200 mA adapters will run these games".
  35. ↑ 35.0 35.1 35.2 35.3 Retro Games Now, "Grandstand Munchman" (retrieved 2026-10-18). Collector's buying guide: windows scratch and sometimes crack, small scratches polish out but cracks cannot be repaired; the title sticker fades, peels or goes missing; check the game on batteries alone as well as on the adaptor, because a damaged power connector "can lock the game in 'mains power only' mode".
  36. ↑ Handheld Museum, "Grandstand Invader From Space" (retrieved 2026-10-18): 1980, VFD, four AA cells, licensed from Epoch. Its page for the Epoch version (model 8020) calls the display LED, which MAME and the V&A record contradict.
  37. ↑ Handheld Museum, "Grandstand Astro Wars" (retrieved 2026-10-18): 1981, VFD, four C cells, model 11183; licensed from Epoch (Galaxy II); two versions, one with "Astro Wars" in red that sits upright in its box; maximum score 10,000.
  38. ↑ 38.0 38.1 Oona Räisänen, "Tomy Electronic PUCKMAN", 3 May 2013 (retrieved 2026-10-18). The Tomy version of Munchman: D-pad controls, on/off and AMA/PRO switches; processor marked D553C-160; four C cells, 6 V; runs from a 6 V adapter wired to the battery terminals.
  39. ↑ Centre for Computing History, Grandstand collection (retrieved 2026-10-18), including CH77112 (The Big Game Soccer, 1981, described as an LED game and "Grandstand's only simultaneous 2 player tabletop game").
  40. ↑ Handheld Museum, "Grandstand Crazy Monster" and "Epoch Zig-Zag Monster" (retrieved 2026-10-18): VFD, four C cells; Epoch's Zig-Zag Monster, 1983, model 36270.
  41. ↑ Handheld Museum, "Grandstand Firefox F-7" (retrieved 2026-10-18): 1983, VFD, four C cells, model 11279; the same game as Epoch Astro Thunder 7, Epoch Galaga X6 and Radio Shack Astro Thunder.
  42. ↑ Victoria and Albert Museum, O27498, "firefox f-7", "Grandstand electronic game" (retrieved 2026-10-18): table game, 1983, made in Japan, "battery operated, hand held; speaker system".


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