Jump to content

Grandstand Astro Wars Capacitor Replacement Guide

From RetroTechCollection
Galaxy II by Epoch, Model 8100, Made in Japan, Copyright 1981 (Electronic Handheld Game)
Epoch Galaxy II, the original of Astro Wars, with the same main board (Joe Haupt, CC BY-SA 2.0).

The capacitors on the main board of the Grandstand Astro Wars and Epoch's identical Galaxy II.[1] No manufacturer's parts list exists as far as can be found. The values below come from a parts list compiled by an owner, bobmoo79, from his own board in 2018, checked against repairers' videos and against photographs of opened boards. Voltage ratings are given only where a repairer read them off the part or a photograph shows them.[2]

Is a recap needed?

[edit | edit source]

Usually not. In the documented repairs the faults were the power transistor S02, the diode S06 or the driver transistor S03, not the capacitors:

  • bobmoo79, codify and Retro Tech Repair each replaced every electrolytic while chasing a fault, and none of those recaps changed the fault.[3][4][5]
  • retro_restos and PghGameFix found the electrolytics good on an ESR meter, including a crusty-looking one, and left them in.[6][7]
  • Two repairers found a failed 330 μF 10 V capacitor: one blown on the +6 V line of a game that also had a failed power transistor and driver transistor, and one leaking and measuring 126 μF on a game that only came back when the power transistor was replaced.[8][9]

Replace a capacitor that has leaked, bulged or vented, or that measures well out of value, and look at S02, S03 and S06 before blaming the capacitors for a dead game. See Grandstand Astro Wars Troubleshooting Guide and Capacitor Failure Symptoms.

Capacitor list

[edit | edit source]
Astro Wars main board (19096) capacitors
Ref Type Value Voltage Where it is Notes
C01 Electrolytic 220 μF Not published Bottom edge, right of the round TY-33 transformer, beside S07 Value from the parts list only[2]
C02 Electrolytic 330 μF 10 V Bottom right corner, below C09 and right of S03 A 330 μF 10 V part failed on two games; one repairer describes his as next to the transformer, so check the printing on your own board[2][8][9]
C03 Electrolytic 47 μF 50 V Bottom left corner, beside ceramic C06 47 μF 50 V printed on the part; measured 0.11 Ω ESR on one game[2][7]
C04 Electrolytic 10 μF 16 V Upper right, between the L03 and L04 speaker-wire pads and S08 Connects S02's emitter to the base of S04; Retro Tech Repair replaced it with a 25 V part[2][3][5]
C05, C06 Ceramic 47 nF (473Z) C05 at the top beside the crystal; C06 bottom left beside C03 [2]
C07 Ceramic 2.2 nF (222K) Below C08, to the right of S02 [2]
C08, C09 Ceramic 1.2 nF (122K) C08 just below S02; C09 above C02 [2]
C10, C11 Ceramic 470 pF (471K) Either side of the 400 kHz resonator X01 at the top of the board [2]

Positions were read from photographs of opened boards by bobmoo79 (Handheld Museum forum, December 2018), bpharoah (April 2023) and codify (June 2019), which all show the same silkscreen; these photographs are not freely licensed and are not reproduced here.[3][10][4] The C03 rating of 50 V is printed on the part in bpharoah's photograph and was also read out in PghGameFix's video. The C04 rating of 16 V comes from Retro Tech Repair, who read it off the part he replaced. The C02 rating comes from the failed parts described by My Mate VINCE and Philip Bryden.[10][7][5][8][9] No source gives the C01 rating; read it off the part.

The parts list does not cover the control board (96062) or the joystick board, and no capacitors on them are mentioned in any repair.[2]

Replacement procedure

[edit | edit source]
  1. Open the case and lift out the main board as described in Opening the case. The board is held by four screws from the front; the battery wires and DC socket have to be freed to take it right out.[9]
  2. Note the polarity of each electrolytic before removing it. The board marks "+" beside each one.[3][10]
  3. Take care round the display. C01 and C03 sit at the lower edge of the board below the glass tube, which must not be bent or levered against.[5]
  4. The board uses leaded solder; fresh leaded solder or flux makes the old joints easier to clear. Old traces and pads lift easily with too much heat.[11][7][8]
  5. Fit capacitors of the same value and the same or a higher voltage. Owners have fitted 25 V parts at C02 and C04. Space under the hood is tight, so keep the replacements no larger than the originals.[9][5][8]
  6. Before refitting the case, power the board from a current-limited 6 V supply and check the current and the temperature of S02 (see below).

Checks after recapping

[edit | edit source]
After the recap
Check Expected Source
Supply current at 6 V About 0.2 A on one repaired game [5]
S02 temperature A little warm, not hot [5]
Microcontroller supply About −10 V [12]
Display supply About −39 V [12]

If S02 heats up quickly and the current rises above an ampere, switch off: that is the S06 fault, not a capacitor problem.[3][12]

[edit | edit source]

References

[edit | edit source]
  1. ↑ MAME source, hh_ucom4.cpp at commit d404316 (retrieved 2026-10-18). Driver notes for Epoch Galaxy II: PCB labels 19096 and 96062; NEC μPD553C microcontroller labelled D553C 153; cyan and red VFD NEC FIP10xM20T, revisions B (no. 1-8) and D (no. 2-21) with different graphics; released in the UK by Grandstand as Astro Wars. The file header notes that VFD colours fade after decades.
  2. ↑ 2.00 2.01 2.02 2.03 2.04 2.05 2.06 2.07 2.08 2.09 bobmoo79, Astro Wars parts list (image posted in the Handheld Museum forum thread "Astro wars / galaxy ii repair", 7 December 2018, edited to January 2019; retrieved 2026-10-18). Compiled by the owner from his board: S02 D882 NPN; S03, S04, S05 C2785 NPN; S06, S07, S08 diodes, type not identified; S09 zener 11.5 V; S10 zener 7.5B2 (7.5 V); transformer TY-33; electrolytics C01 220 μF, C02 330 μF, C03 47 μF, C04 10 μF (no voltages given); ceramic C05, C06 47 nF (473Z), C07 2.2 nF (222K), C08, C09 1.2 nF (122K), C10, C11 0.47 nF (471K); resistor packs R01 95k, R02-R04 92k, R05 22k (five 22k resistors, no common pin); R06 333 Ω, R07 620 Ω, R08 2.2k, R09 3.9k, R10 8.2k, R11 1M; X01 400 kHz; display FIP10DM20T; microcontroller D553C-153.
  3. ↑ 3.0 3.1 3.2 3.3 3.4 Handheld Museum forum, "Astro wars / galaxy ii repair", pages 1-2, December 2018 - February 2019 (retrieved 2026-10-18). Owner bobmoo79's dead white-lettered Astro Wars: the D882 ran very hot, the supply fell to about 1.5 V and the game drew 1.5-1.7 A; a replacement D882, then all new transistors and all new electrolytic capacitors, made no difference; S06 read about 20 Ω both ways; with S06 lifted the μPD553 received its −10 V and ran when the display was fed separately; an S06 taken from a working red-lettered game ("a slightly different PCB revision") cured it. S06 is a glass diode with no printing, its cathode on transformer pin 1; with the good part fitted about 10 mA flows through it at 39 V; 32 V and 39 V zeners overheated. Transformer connections traced: pins 1, 2 and 5 ground, pin 3 +6 V, pin 4 S02 collector, pins 6 and 10 the display filament (display pins 1 and 30). Also a μPD553-to-display pin map credited to kevtris and an out-of-circuit display test (about 3 V on the filament, 12 V on a grid and a segment) whose voltages the owner did not guarantee. Other members: a healthy game should draw "more like 100mA" (blanka); the wrong AC adapter "will usually fry" a transistor, "the most frequent damage I've seen to VFD games" (Rik, site administrator).
  4. ↑ 4.0 4.1 Andy van Stokkum, "Repairing an Astro Wars", codify.nz, 15 June 2019 (retrieved 2026-10-18), with photographs of the opened game. S02 ran hot and was replaced; the game worked for about a month, then S02 failed again and S03 ran hot; finally replaced S06 (140 V zener; 2 W parts fitted where a 500 mW 1N5275B would do), S03-S05 (2SA1175), S02 (D882) and "all electrolytic capacitors (as labelled)". 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 less bright than at 6 V.
  5. ↑ 5.0 5.1 5.2 5.3 5.4 5.5 5.6 Retro Tech Repair, "Astro Wars Repair (sound but no display or faint display)", YouTube, 29 January 2021 (transcript read 2026-10-18). Faint sound and no display on several games. Measured on a working board: about −1.5 V at the D882 base, −3 V at the base of S03 (a C945), fed from a −9 V line through the zener S09, and the −10 V microcontroller supply (24:00-33:00). A 10 μF capacitor next to the transistor and transformer, rated 16 V, was replaced with a 25 V part, and later the whole board was recapped, without effect (21:00-31:00). Earlier boards, with the Epoch logo, have one diode S06 under the display; later boards have two, S06 and S11, in series (39:00-46:00). The removed diodes broke down at about 140-143 V when tested on a stack of 9 V batteries, which he warns is not safe (48:00-54:00). On a Japanese Astro Wars ruined by the wrong charger, the D882 was burnt; a new D882 still overheated until S06 was replaced with a 1N5275B; the game then drew about 0.2 A with the D882 a little warm, and ran for several hours (57:00-67:00). S06 sits under the bottom edge of the display; bending the tube risks cracking it (61:00). The flat cables to the joystick board and power board broke after repeated handling (39:00).
  6. ↑ retro_restos, "Astro Wars Repair No Power & Broken Joystick", YouTube, 12 June 2023 (transcript read 2026-10-18). Adaptor: 6 V, negative tip (2:00). About seven screws, the middle one smaller; screws that do not drop out; the base tray is pulled forward to free the case (2:00-4:00). The fire button spring had come out of place; the power switch leaves were cleaned with alcohol and bent slightly (4:00). The batteries run through the DC socket, which disconnects them when a plug is inserted; continuity across the two red wires with no plug in (6:00). Four screws free the display (7:30). The D882 read as a resistor; a new one restored sound and display; the electrolytics tested good on an ESR meter and were left alone (10:00-13:00). Carbon pads cleaned with alcohol, switch cleaner on the joystick (14:00). The three-wire joystick cable had been snapped at the joystick board by an earlier repairer; trimmed and resoldered (18:00-22:00). The display appears to flicker on camera because of the shutter speed, not in real life (18:00, 24:00).
  7. ↑ 7.0 7.1 7.2 7.3 PghGameFix, "Try To Fix Ep2: Epoch Galaxy II (Grandstand Astro Wars)", YouTube, 12 October 2021 (transcript read 2026-10-18). A water-damaged Galaxy II with rusted contacts: four screws inside the case; wires to be desoldered before the boards come out (8:16-9:33). A crusty electrolytic marked 47 μF 50 V measured 0.11 Ω ESR in circuit, within specification; no other capacitor showed leakage (13:03-15:36). The battery feed is cut by a switch inside the DC socket (33:26). Sound but no display: a cracked glass diode at S10 (marked B1 and apparently 7.5) was replaced with a zener of unknown value from another device and the display returned (34:20-42:20).
  8. ↑ 8.0 8.1 8.2 8.3 8.4 My Mate VINCE, "1981 Grandstand ASTRO WARS Tabletop Game - No Power Fault - Trying to Fix", YouTube, 10 January 2021 (transcript read 2026-10-18). A previous owner had found a 330 μF 10 V capacitor blown on the +6 V line and replaced it, all the capacitors and the power transistor, but the new transistor kept overheating (0:00-3:00). The DC socket's battery contact did not reconnect the cells: a spring leaf rests on a shelf inside the riveted socket and the plug pushes it away; it was reformed and soldered as a temporary repair (6:00-21:00). Flat-cable joints and lifted pads were repaired with wire (12:00). The small transistor that drives the power transistor's base (marked C945) had a base-collector short; with it replaced the game ran, but the display was too dim to see and the power transistor ran very hot; a different power transistor (a BD139 as a stopgap) made the display bright. He concluded that the original faults were the blown capacitor, the small transistor and the power transistor (24:00-39:00). With a heatsink added to the power transistor, the board "just about fits but it is quite tight" in the case (33:00).
  9. ↑ 9.0 9.1 9.2 9.3 9.4 Philip Bryden, "Trying to fix a Grandstand Astro Wars (Super Galaxian, Galaxy 2) 1981", YouTube, 19 March 2024 (transcript read 2026-10-18). First game: the DC socket switches the positive battery lead and its dirty contact stopped battery operation; contact cleaner cured it (3:09-5:56); a piezo wire had broken off (6:49); the power switch only worked once the control section was screwed down properly (12:40-15:16). Second game, completely dead and drawing no current: a leaking 330 μF 10 V capacitor next to the transformer measured 126 μF and was replaced with 330 μF 25 V, without curing it (27:04-31:02); three C945 small transistors tested good (36:03-37:49); the NEC D882 had failed and a new one cured it (38:13-41:24). Four screws hold the silver hood and three smaller screws the control section; hold the control panel and pull the hood forward; the board is held by four screws from the front; the battery wires are unsoldered, negative at the top and positive at the bottom (22:00-26:31). Reassembled upside down the piezo falls out, so he taped the buttons in instead (9:04-10:09).
  10. ↑ 10.0 10.1 10.2 bpharoah, "More Astro Wars!", 24 April 2023 (retrieved 2026-10-18), with photographs. A dead game: 6 V with negative polarity at the DC socket; traced on the red wire to the power switch, bridged with a crocodile clip, and through the control panel cable to the main board; no leaking or bulging capacitors; the D882 power transistor had a base-emitter short; a new transistor cured it.
  11. ↑ My Mate VINCE, "Dead 1981 Grandstand Astro Wars Game - Repair Video", YouTube, 31 December 2023 (transcript read 2026-10-18). Seven cross-head screws on the underside; the top separates from the bottom with some prying (1:42). Slight corrosion and brown battery leakage under a spring, cleaned with a rotary tool (0:45, 17:01). The red battery wire runs through the DC socket's switch, which cuts the batteries when a plug is in and can stop them reconnecting when dirty (2:51-3:46). He judged the display good because its getter was still black, adding that a cracked tube goes whitish (2:16). The D882 had a 3 Ω short; it and the C945 next to it were replaced and the game worked (7:39-17:47). The board has a conformal coating (16:26).
  12. ↑ 12.0 12.1 12.2 All About Circuits forum, "Grandstand Astro Wars Game (Faulty) - help with component identification", February 2019 - January 2024 (retrieved 2026-10-18). bobmoo79: the circuit takes 6 V and makes −10 V for the microcontroller and −39 V for the display (measured on a working game); with the failed S06 the D882 (S02) gets very hot, the supply drops to about 2.5 V and the game draws 1.5 A; S06 is an orange glass diode with a red and a brown band (another member's has a single red band). Later posts: one member fixed the same fault with a 1N5275B zener; another fixed a game he had damaged in about 1985 with "the wrong mains brick" by replacing S06.


Retrieved from "https://wiki.retrotechcollection.com/index.php?title=Grandstand_Astro_Wars_Capacitor_Replacement_Guide&oldid=26287"