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Grandstand Star Force General Maintenance

From RetroTechCollection
Grandstand Star Force Instructions controls drawing
The Star Force controls as drawn in Grandstand's booklet, with the adaptor plug going into the socket on the right-hand side.

Care and maintenance of the Grandstand Star Force, the space game with a multicoloured vacuum fluorescent display (VFD) that Epoch made and Grandstand sold in the UK from about 1984; a dealer's museum list calls it the last in Grandstand's arcade series.[1][2] Epoch sold it under the same name, and a collector identifies the Yeno Super Galaxy II as the same game.[1][3]

Much less has been published about Star Force than about Astro Wars or Firefox F-7. There is Grandstand's booklet, the Handheld Museum's reading of the microcontroller, a museum record of the box, and two repair videos whose narration could not be retrieved; their descriptions are cited where they help. No service manual, schematic, board photograph or written repair has been found. Faults are on Grandstand Star Force Troubleshooting Guide.

The Star Force at a glance

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Star Force: what is known
Part Detail
Cells Four C cells (Duracell MN1400)[4]
Adaptor Grandstand Universal Mains Adaptor with its polarity switch set to negative; no voltage printed[4]
DC socket On the right-hand side of the case[4]
Battery contacts The same part as in Astro Wars[5]
Battery cover The Epoch cover shared with Astro Wars, Scramble and Firefox F-7[6]
Microcontroller NEC D7528C-016, as read by the Handheld Museum[1]
Display Multicoloured VFD; part number not recorded[7]
Controls Joystick (left and right), firing button, START, skill level select, phase select, and POWER and SOUND slide switches[4]

Before you start

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  • Remove the four C cells first.[4]
  • The microcontroller is from the same NEC D7528C family as the Firefox F-7's (D7528C 011 on an owner's schematic of that game), not the μPD553 of Astro Wars and Scramble.[1][8] Do not assume part numbers or voltages from Astro Wars apply until you have compared the boards.
  • The screen mount can break: one of the two repair videos lists a broken screen mount among its faults.[9]

Opening the case

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No written account of opening a Star Force has been found. retro_restos published a full teardown in 2023 and Repairing Faulty Tech opened one in 2025; both are on YouTube, but their narration could not be retrieved to check the steps here.[9][10] Until those steps are confirmed, look for screws in the base, as on the other Epoch games, and do not force the case apart.

Cleaning

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  • Grandstand's care note: move the joystick gently, do not press hard on the firing button, keep the game out of the sun and do not let it get wet.[4]
  • retro_restos described his game as grubby and cleaned it during the repair; the video description does not say how.[9]

Batteries and battery contacts

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The game takes four C cells; Grandstand recommends Duracell MN1400 and says it will not work properly on weak batteries. If the game malfunctions or the display is erratic, check or replace the cells, and take them out if the game will not be used for a long time.[4]

  • The battery contacts are the same part as Astro Wars'. retro_restos considered taking a spring from a Star Force to repair an Astro Wars, so a stretched or corroded spring can be reformed or swapped between the two games.[5]
  • The 3D-printable Epoch battery cover is listed by its designer as fitting Star Force.[6]

DC socket and adaptor

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The booklet's drawing shows the adaptor plug going into a socket on the right-hand side. For mains use it names the Grandstand Universal Mains Adaptor, not included, with its polarity switch set to negative, and gives no voltage.[4] No Epoch rating for Star Force has been found. For Galaxy II and Astro Thunder, the other Epoch games whose ratings survive, Epoch and Radio Shack specify 6 V DC with the centre pin negative.[11][12] Measure any adaptor before connecting it. See Grandstand Universal Mains Adaptor.

One of the two repaired games had an intermittent power socket.[9]

Controls

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  • The joystick moves the Space Fighter left and right only.[4]
  • SOUND is a slide switch: with it off, the game plays in silence.[4][7]
  • The skill level and phase select buttons are used before a game starts.[4]
  • One repaired game had unresponsive controls and a faulty joystick; the description does not say what cured them.[9]

Display

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The Star Force has a multicoloured VFD.[7] Its part number and supply have not been published. As with the other VFD games, keep it out of the sun.[4] The Handheld Museum's administrator, writing about Epoch VFD games in general, has never had a display fail unless its glass was broken; they fade unevenly over years of heavy use.[13]

Storage

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  • Take the cells out.[4]
  • Keep the game dry and out of the sun.[4]

Preventive maintenance checklist

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  1. Check the cells and the battery springs.
  2. Measure any adaptor before use, and set a Universal Mains Adaptor to negative.
  3. Check that SOUND is on before deciding the game is silent.
  4. Try every control, including the phase and skill level buttons, before a game.
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References

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  1. ↑ 1.0 1.1 1.2 1.3 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.
  2. ↑ Retro Games (Chillout Games), "Grandstand" museum page (retrieved 2026-10-18): Star Force 1984, "the last in the arcade series" of Grandstand's tabletop games.
  3. ↑ Handheld Museum forum, "Epoch Star Force", 2012-2019 (retrieved 2026-10-18), high-score thread: the game is fast; a member notes that the uncommon Yeno Super Galaxy II is "the same as Epoch and Grandstand's Star Force".
  4. ↑ 4.00 4.01 4.02 4.03 4.04 4.05 4.06 4.07 4.08 4.09 4.10 4.11 4.12 4.13 Grandstand, Star Force instruction booklet (distributed by Adam Imports Ltd, Ripon Way, Harrogate, a member of the Adam Leisure Group PLC; printed in Japan; no date printed), hosted here as File:Grandstand Star Force Instructions.pdf (PDF page numbers). p. 1: drawing of the controls (power switch, sound switch, firing button, joystick, skill level select, start and phase select buttons) with the adaptor plug entering a socket on the right-hand side, and the batteries box: four Duracell MN1400 cells; the Grandstand Universal Mains Adaptor, not included, with its polarity switch set to negative; the game will not work properly on weak batteries; if it malfunctions or the display is erratic, check or replace the batteries; switch off after play and remove the batteries when the game is not used for long periods; care note: "move the Joy Stick gently. Do not press hard on the Firing Button ... Do not leave in sun or allow it to get wet." At switch-on an electronic melody plays and the display lights; the game is set to skill level 1 ("L1" at the top of the display) and phase 1; with the sound switch OFF the game plays without sound effects; START sounds and shows the number of lives. p. 2: the joystick moves the Space Fighter left and right. p. 6: the game ends with no lives left or at the perfect score of 3,000.
  5. ↑ 5.0 5.1 retro_restos, "Grandstand Astro Wars Service & Repair from Ebay Vintage Games Bundle", YouTube, 2 October 2024 (transcript read 2026-10-18). Strip-down service: carbon contacts cleaned; power slider contacts bent for spring and greased; fire button spring stretched slightly (2:00-4:00). A stretched battery spring was unsoldered, reformed with pliers and refitted; the Star Force has "exactly the same battery contact" (4:00-8:00). The Fresnel screen, star backdrop and front screen come out; the front screen was polished and its back cleaned with glass cleaner (10:00-12:00). "Astro Wars is notorious for throwing the batteries out when you're trying to put them in" (16:00).
  6. ↑ 6.0 6.1 YoxxxoY Jorge, "Battery cover Epoch electronic games", Thingiverse 3399673 (2 February 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. Licensed CC BY.
  7. ↑ 7.0 7.1 7.2 Centre for Computing History, "Star Force Electronic Space Battle", CH36762 (retrieved 2026-10-18): Grandstand; box text "Multi-coloured fluorescent display. Four skill levels. Seven phases. Joystick fighter control. Dramatic sound effects. Optional silent mode. Uses four Duracell MN1400 alkaline batteries or Grandstand Universal Mains Adaptor."
  8. ↑ Philip Bryden, "Grandstand Firefox F7" schematic, three sheets ("Power rail", "Data", "Control Board"), KiCad 6, revision 1, 8 June 2022, PDF on MEGA linked from his video (retrieved 2026-10-18). Drawn by the owner from his own boards and described by him as a first attempt that may need revision. It shows the microcontroller labelled D7528C 011 and a second chip labelled D1771C 011; the display labelled 7AM33T, with its filament on display pins 1 and 2 and 30 and 31; a ten-pin transformer TX-30 driven by transistor S04 (882), whose base is driven by S03 (C945); diodes S05 to S12; electrolytic capacitors C01 to C04 and other capacitors C05 to C15, without values; a 5 MHz resonator X01 (FCR5.0M); and a ten-way cable L01 to the control board, carrying 6 V DC on pin 4. Control board: the power switch; up, down, left and right joystick contacts; select, start and fire; a "sound L" switch for the small piezo speaker and a "sound R" switch for the large one; and a switched DC socket whose centre pin is the negative (ground) side.
  9. ↑ 9.0 9.1 9.2 9.3 9.4 retro_restos, "Vintage Electronic Grandstand Star Force Teardown & Repair. Broken Screen, Power Fix & Bad Joystick", YouTube, 21 June 2023 (description read 2026-10-18; the transcript could not be retrieved): "a rare opportunity to see inside the Star Force game"; the game was grubby, with an intermittent power socket, a broken screen mount and unresponsive controls, which the video works through.
  10. ↑ Repairing Faulty Tech, "Grandstand STAR FORCE 80's game won't power on - Can I fix it?", YouTube, 13 April 2025 (description read 2026-10-18; the transcript could not be retrieved): a Star Force that would not power on; the description does not give the fault or the outcome.
  11. ↑ Epoch, Galaxy II instruction leaflet (Epoch Corporation, Englewood, New Jersey; © 1981 Epoch Co. Ltd, Tokyo; made in Japan), hosted here as File:Epoch Galaxy II Instructions.pdf. p. 2: four C cells with the + and − ends aligned, or an AC-DC adapter of 6 V DC, 250-300 mA, with a polarity symbol showing the centre pin negative; the same controls as the Grandstand game.
  12. ↑ Radio Shack, Astro Thunder owner's manual (cat. no. 60-2197; 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 in the compartment on the bottom, 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; take them out if the game will not be used for a week or more, because "even leak-proof type batteries can leak damaging chemicals, which will ruin your unit permanently"; the drawing shows the adapter jack on the right-hand side. p. 2: the LEFT SOUND switch turns the musical sound on and off and the RIGHT SOUND switch the sound effects. p. 7: maintenance: keep it dry, out of heat, dirt and dust; do not drop it; no harsh chemicals, solvents or strong detergents, only a damp cloth; use fresh cells of the correct type.
  13. ↑ Handheld Museum forum, "EPOCH Astro Command - dead or dying", January 2016 (retrieved 2026-10-18). Rik (site administrator): an Epoch VFD game will play and make its sounds even without the display or the small transformer that powers it; he has never had a VFD die unless its glass was broken; with heavy use the displays fade, unevenly, over years; a broken filament wire leaves an area of the display very dim; a dead game is normally a transistor or two blown by an incorrect power supply. The owner of the Astro Command (the Epoch version of Grandstand Scramble) found its supply runs from the control board to the main board through a flat cable, which frayed and broke after the board had been turned over repeatedly.


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