Grandstand Tron Troubleshooting Guide
Fault-finding on the Grandstand Tron, Tomy's Tomytronic Tron distributed in the UK by Grandstand.[1] No service manual, schematic or board photograph of this game has been published, and only one fault specific to Tron has been reported. Below are what a working game does, the figures that are known, and the checks that can be made from the outside; where a step depends on parts nobody has documented, that is stated. Cleaning and the adaptor rating are on Grandstand Tron General Maintenance.
What a working game does
[edit | edit source]- Switch on: a pattern moves across the screen and a fanfare sounds.[2]
- The first screen shows four Tron figures on the left, four Sark figures and three red and green enemy light cycles on the right, the MCP at the far right, and a score of 0.[2]
- Play runs through the Light Cycle game, the Ring game and the MCP game in turn; the CONTROL disc steers and SPEED/SHOOT accelerates or throws the disc.[2]
Known figures
[edit | edit source]| Point | Value | Source |
|---|---|---|
| Batteries | Four C alkaline cells, 6 V | Tomy leaflet[2] |
| Adaptor (Tomy) | 7.5 V DC, 200 mA, 2.1 mm plug, centre negative | Tomy leaflet[2] |
| Microcontroller | Hitachi HD38800A88 | MAME[3] |
| Clock | About 400 kHz (MAME's figure, marked as an approximation) | MAME[3] |
| Display | NEC FIP10AM24T no. 2-8 1 | MAME[3] |
No voltages measured inside a Tron have been published.
Symptom table
[edit | edit source]| Symptom | Likely cause | Action | Source |
|---|---|---|---|
| Runs on an adaptor but not on batteries | Battery terminals corroded by leaked cells | Clean or replace the terminals; check the leads | [4] |
| Display dark and play goes wrong | Weak cells | Fit fresh alkaline C cells | [2] |
| Dead on batteries and on a known-good adaptor | Not documented for this game | Check the adaptor polarity and the switch; see below | [2] |
| Died after a different adaptor was used | Reversed polarity or excess voltage | Usually a blown transistor in VFD games of this period; the Tron's own supply parts are undocumented | [5] |
| Score shows green bars instead of a number | Normal: each 2,000 points shows as a green bar | None | [2] |
| Faded colours | Phosphor wear | Not repairable | [6] |
Dead on both supplies
[edit | edit source]- Fit fresh alkaline cells and measure 6 V across the battery terminals, then measure the voltage reaching the leads beyond them.[2]
- Measure the adaptor: 7.5 V, centre negative.[2] A reversed or over-voltage adaptor can damage these games.[5]
- Work the ON/OFF switch several times and try again.
- Beyond this point nothing about the Tron's circuit has been published. Look through the smoked case for leaked electrolyte, burnt parts or broken wires before opening it.[7]
- The program is mask-programmed into the HD38800A88, and MAME lists no other game that uses that chip, so a failed microcontroller can only be replaced from another Tron, Tomy's or Grandstand's.[3]
Sound but no display
[edit | edit source]A Tron that sounds its switch-on fanfare without the moving pattern on the screen has a running microcontroller, which leaves the display's supply or the FIP10AM24T tube. In VFD games of this period the Handheld Museum's administrator has only seen tubes fail when the glass was broken,[8] and the Tron's smoked case lets you inspect the glass for cracks before opening it. No account of a Tron display-supply repair has been published.
Things that are not faults
[edit | edit source]- Scores above 1,995 appear as green bars at the top of the screen, one for each 2,000 points, up to 15,995; the score then returns to 0 and the game continues.[2]
- The game speeds up each time all three games are completed, up to six times.[2]
- At most five Trons can be held at once, however many extra are earned.[2]
- The circuitry visible at the back of the case is imitation, not part of the electronics.[7]
What is repairable
[edit | edit source]- Repairable: corroded battery terminals and the case.[4][9] The control contacts can be cleaned once the case is open, though no Tron account of it has been published.
- Replaceable only from a donor Tron: the HD38800A88 microcontroller and the FIP10AM24T display.[3]
- Not repairable: a cracked display tube, faded phosphor.[8][6]
Related pages
[edit | edit source]- Grandstand Tron
- Grandstand Tron General Maintenance
- Grandstand Munchman Troubleshooting Guide
- Grandstand Caveman Troubleshooting Guide
- Grandstand Universal Mains Adaptor
References
[edit | edit source]- ↑ Handheld Museum, "Grandstand Tron" (retrieved 2026-10-18): 1981, VFD, four C batteries, model 11266; "Grandstand was the distributer for Tomy's Tron in the U.K."; photographs of the Grandstand-branded game, with "GRANDSTAND TRON" on the bezel and "TOMY" on the front of the base, and of its box ("Code No. 11266", Tomy, "Three electronic games in one").
- ↑ 2.00 2.01 2.02 2.03 2.04 2.05 2.06 2.07 2.08 2.09 2.10 2.11 2.12 Tomy Corporation, Tomytronic Tron instructions, no. 7601, copyright 1982 Tomy Corp., Carson, California, and MCMLXXXI (1981) Walt Disney Productions; printed in Japan. Hosted here as File:Tomy Tron Instructions.pdf. Page 2: "Illustration 1", the battery cover lifted on the underside with four C cells in two rows; "Set the On/Off switch to the Off position. Turn the game over and lift the battery cover ... Insert four 'C' size Alkaline batteries"; recommended AC adapters Archer cat. no. 270-1551 A and Recoton AD-10UL; adapter requirements 7.5 V DC 200 mA, 2.1 mm ID coaxial plug, tip (centre) polarity negative; "Illustration 2", the CONTROL button (right, up, left, down), the ON/OFF switch and the SPEED/SHOOT button; at switch-on "a pattern will move across the screen and a fanfare will sound", then the first screen shows four Tron figures, four Sark figures, three red and green enemy light cycles, the MCP and a score of 0. Pages 3-5: the Light Cycle, Ring and MCP games; the skill level rises after all three are completed, up to six times. Page 6: scores above 1,995 shown as green bars, maximum 15,995 then back to 0; an extra Tron at 2,000 points, at most five; care: no excessive heat or cold, avoid wet or dirt, "Don't take it apart", don't shake or drop, turn off and remove the batteries for storage, no dead batteries left in; "If the batteries become weak the display screen will become dark and show incorrect action".
- ↑ 3.0 3.1 3.2 3.3 3.4 MAME source, hh_hmcs40.cpp (retrieved 2026-10-18). Driver notes for Tomy Tron: made in Japan; PCB label THN-02 2E114E07; Hitachi HD38800A88 microcontroller, 1-bit sound; cyan/red/green VFD NEC FIP10AM24T no. 2-8 1. The chip list dates the HD38800A88 to 1982 and lists it for Tomy Tron (THN-02) only. Inputs: four directions read through a multiplexed interrupt, and one button; the machine configuration clocks the chip at 400 kHz, marked in the source as an approximation.
- ↑ 4.0 4.1 Keeper1st, "TRON hand-held electronic game (Tomytronic, 1982)", YouTube, 19 December 2010 (video description, retrieved 2026-10-18): "I had left the batteries in it. The batteries since had expanded and leaked, making a big mess and corroding the battery terminals to the point where batteries cannot power the game anymore. But thankfully it has a jack for an external power supply!"
- ↑ 5.0 5.1 Handheld Museum forum, "Astro wars / galaxy ii repair", December 2018 - February 2019 (retrieved 2026-10-18). The site administrator (Rik), writing about VFD tabletop games in general: the wrong AC adapter "will usually fry" a transistor, "the most frequent damage I've seen to VFD games"; keep rubber buttons, springs and speakers from scrapped games as spares.
- ↑ 6.0 6.1 MAME source, hh_ucom4.cpp (retrieved 2026-10-18), file header on VFD games: NEC FIP part numbers give the number of grids after "FIP"; "after decades passed, all the colors fade". Also the driver notes for Tomy Pac-Man (NEC uCOM-43, D553C 160) and Tomy Caveman (NEC uCOM-43, D553C 209, PCB TN-12 2E114E03).
- ↑ 7.0 7.1 Handheld Museum, "Tomy Tron" (retrieved 2026-10-18): 1981, VFD, four C batteries, model 7601; "the entire case is made of a smoked clear plastic so you can see the inside of the game (and it has some large, simulated circuitry in the back...)"; released by Grandstand in the UK.
- ↑ 8.0 8.1 Handheld Museum forum, "EPOCH Astro Command - dead or dying", January-February 2016 (retrieved 2026-10-18). The site administrator (Rik), writing about VFD tabletop games in general: the games play and make their sounds without the display; displays fade unevenly with heavy use; he has never had a display fail unless the glass was broken.
- ↑ GenXGrownUp, "1981 Tron Handheld from Tomytronic in LIKE-NEW CONDITION!", YouTube, 29 June 2023, 8:58 (watched 2026-10-18; no transcript available; chapters "Hardware Tour" 1:31, "Original Manual" 3:06, "Clean-Up" 3:58, "Power On!" 5:33). Shown: the smoked case, with imitation circuit patterns visible through the rear of the hood; the battery cover on the underside carrying a printed instruction label, and the empty battery box with contacts for four C cells in two rows; the panel and case seams cleaned with a cleaning putty; sticker residue on the smoked rear removed with Goo Gone and a microfibre cloth; the game powered on with fresh C cells.