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Grandstand TV Game 3600 Mk II Troubleshooting Guide

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Adman Grandstand 3600 MK II Colour (14)
Component side of a working 3600 Mk II: the AY-3-8500 left of centre, the 2 MHz crystal at the far left, the 4.433618 MHz crystal and green trimmer at top right beside the screened RF section, and the adjustable coils below it.

Fault-finding for the Grandstand TV Game 3600 Mk II, the Hong Kong-made colour Pong console with a light gun built on General Instrument's AY-3-8500.[1] No fault report for a 3600 Mk II in particular has been found; the console photographed for Wikimedia Commons works.[2] The checks below use the owner's description of how the console behaves, the board photographs, and General Instrument's 1978 data for the AY-3-8500, which gives exact values for the chip's supply, clock and inputs. Opening the case and routine care are on Grandstand TV Game 3600 Mk II General Maintenance.

What should happen at power-on

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With six good C cells or a 9 V adaptor, POWER switched on and an analogue television tuned to the console:

  • A colour picture appears: a green playing field, coloured bats and two-digit scores at the top.[3][2]
  • The two GAME SELECT switches choose tennis (A-B), football (A-D), squash (B-C) or practice (C-D).[4]
  • The target games (TARGET 1 and TARGET 2) appear only when the light gun is plugged into the right side of the case.[2][4]
  • With BALL SERVE on AUTO the ball is served by itself; on MANUAL the game stops after each point until SERVE is pressed.[4][5]
  • The speaker gives three different tones: one when a bat hits the ball, a lower one off a wall and a higher one on a score.[5]

Expected measurements

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3600 Mk II reference values
Point Expected Source
Supply at the cells or adaptor 9 V; adaptor rated 100 mA [6]
AY-3-8500 pin 4 to pin 2 +6 to +7 V [5]
AY-3-8500 supply current 40 mA typical, 60 mA maximum [5]
Pin 17 clock 2.012160 MHz ±1% (crystal marked 2.000000) [5][1]
Colour subcarrier 4.433619 MHz ±50 Hz [7]
Closed switch contact to ground 1 kΩ or less [5]

For a console that has been in storage, use a bench supply at 9 V with a current limit of about 150 mA. The label asks for a 100 mA adaptor, so a draw far above that points to a short.

Symptoms

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3600 Mk II symptoms
Symptom Likely cause Action Source
Nothing on cells or adaptor Flat or corroded cells; POWER switch; supply section Measure 9 V at the cells and after the POWER switch, then pin 4 of the AY-3-8500. [5]
Works on cells, not on the adaptor Adaptor polarity or voltage; dirty left-side socket The owner gives the socket as centre positive. Measure the adaptor before connecting it again, and clean the socket. [2][8]
Snow on the television Wrong channel or no analogue tuner; RF lead The label gives no channel. Tune slowly across the UHF band; GI's standard modulator channel was E36. Check the RF lead and its clip. [6][7]
Black and white picture, or colour that flickers or comes and goes Television's colour setting or fine tuning; subcarrier off frequency; fault in the colour section Fine-tune the set first. Then measure the subcarrier with a frequency counter: it must be within ±50 Hz of 4.433619 MHz. Only then consider the green trimmer beside the 4.433618 MHz crystal, and mark it before turning. [7][1]
Picture detail doubled or smeared sideways on some televisions 2 MHz game clock off frequency GI warns that delay-line PAL sets show this when the clock is wrong. Measure pin 17. [7][5]
Steady coloured screen but no game The AY-3-8500 is not running Measure pin 4 (+6 to +7 V) and pin 17 (2 MHz). [5]
One bat missing, jumping or stuck Controller potentiometer or lead; socket Swap the two controllers between LEFT PLAYER and RIGHT PLAYER. If the fault moves, it is in the controller; if it stays, check the socket and the board. [4][2]
Football with a third bat on the right No game selected: a GAME SELECT contact is open With none of its games selected the AY-3-8500 plays an undocumented seventh game, Handicap, in which the right-hand player has a third bat. Clean the A/C and B/D switches. [9]
A setting has no effect Dirty slide switch The chip needs 1 kΩ or less through a closed contact. Clean the switch and measure it. [5]
Target games do not appear with the gun plugged in Gun plug or right-side sockets The target games come up only when the gun is connected. Clean the twin plug and both sockets and check the lead. [2][10]
Gun never scores a hit Testing on a flat-panel television; lens; trigger; lead Test on a CRT television. The gun circuit sends pulses to pins 26 (shot) and 27 (hit); check for them when the trigger is pulled. [5]
Scores will not reset, or SERVE does nothing Dirty spring contact under the button Clean the spring contacts on the V-7 plate. The chip's reset (pin 25) and serve (pin 8) inputs work by being pulled to ground. [1][5]
No sound Speaker, its connections or the sound driver The TOA 8 Ω speaker is on the board. The chip's sound comes out on pin 3. [1][5]

Known faults reported for this device

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No repair report for a TVG-3600 Mk II has been found. The console photographed on Wikimedia Commons works and gives a colour picture,[2] and the second example in the South-West Retro Computing Archive is shown complete and boxed, with no fault recorded.[11] The one thing on the photographed board worth attention is a patch of light-coloured deposits in the corner beside the "SE 10 V" electrolytic.[1]

Things that are not faults

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  • Only four games appear: the two target games need the light gun plugged in.[2]
  • The Centre for Computing History calls its example a "four-game" console;[12] the panel lists four bat-and-ball and two target games.[4]
  • On MANUAL serve the game waits after every point.[5]
  • The light gun does nothing useful on a flat-panel television.
  • The game key letters are combinations of the two GAME SELECT switches, not separate positions.[4]

What is realistically repairable

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Repairability of 3600 Mk II parts
Part Repairable? Notes
Electrolytics, resistors, small transistors Yes Through-hole parts on a single-sided board; see Grandstand TV Game 3600 Mk II Capacitor Replacement Guide.[13]
Slide switches, sockets, button contacts Yes Clean first; the switches and controller sockets are soldered to the board.[1]
Hand controllers Yes Separate, so a spare can be swapped in for testing.
Crystals Yes 2.000000 MHz and 4.433618 MHz are ordinary values.[1]
Colour and RF section With care Built from discrete parts under a screen, with a trimmer and adjustable coils; it needs a frequency counter to set up.[1][7]
AY-3-8500 Only by transplant Out of production, but used in hundreds of different consoles, so a donor is the realistic source.[9] Rule out supply, clock and switches first.
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References

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  1. ↑ 1.0 1.1 1.2 1.3 1.4 1.5 1.6 1.7 1.8 Photograph by José Antonio Ortigueira Amor, File:Adman Grandstand 3600 MK II Colour (14).jpg (CC BY 4.0, from Wikimedia Commons; larger copy on the owner's blog), examined at full size: component side of the board with "GI AY-3-8500 7831 TAIWAN", Motorola "MC14075B", "CD4069UBE RCA 827", crystals "2.000000 K.D.S" and "4.433618 K.D.S", a green trimmer beside the 4.433618 MHz crystal, a screened section at one end holding a transistor, an air-wound coil and the RF lead, three adjustable coils in metal cans, a "TOA 8 Ω" speaker, seven slide switches along one edge, two board-mounted sockets, a metal plate marked "V-7" carrying two spiral spring contacts, and five electrolytic capacitors: a blue one marked "220 µF" on the switch edge, two blue ones at the end beside the 2 MHz crystal, a blue one marked "SE 10 V" in the corner below it, and a small light-blue one beside the green trimmer. Light-coloured deposits are visible in the corner near the "SE" capacitor.
  2. ↑ 2.0 2.1 2.2 2.3 2.4 2.5 2.6 2.7 José Antonio Ortigueira Amor, "Adman Grandstand TV Game 3600 MK II Colour (1978)", Retro Ordenadores Orty (collector's blog, in Spanish), 23 November 2023 (retrieved 2026-10-18). The owner's description of his console: General Instrument AY-3-8500 with a Motorola MC14075B and an RCA CD4069UBE; two separate hand controllers that plug into LEFT PLAYER and RIGHT PLAYER sockets near the front edge; a socket on the left side for an external 9 V DC supply, centre positive; a jack and a mini-jack on the right side for the light gun; the RF lead leaves the rear; six 1.5 V C (LR14) cells in an internal compartment reached through the lower case; four screws hold the lower case, and removing it exposes the back of the board, which is held to the upper case by two screws; the console works and gives a colour picture; only the four bat-and-ball games are available until the light gun is plugged in, when the target games appear; the 3600 series had three models (TVG 3600, Mk II and Mk III).
  3. ↑ Photograph by José Antonio Ortigueira Amor, File:Adman Grandstand 3600 MK II Colour (9).jpg and the other screen photographs in the same Wikimedia Commons series (CC BY 4.0): the console's picture on a colour television, a green playing field with coloured bats and two-digit scores.
  4. ↑ 4.0 4.1 4.2 4.3 4.4 4.5 Photograph by José Antonio Ortigueira Amor, File:Adman Grandstand 3600 MK II Colour (3).jpg (CC BY 4.0, from Wikimedia Commons): the panel, with POWER (OFF/ON), BALL SERVE (MANUAL/AUTO), BALL SPEED, BALL ANGLE and PLAYER SIZE under AMATEUR and PROFESSIONAL, GAME SELECT switches A/C and B/D, the game key (TENNIS A-B, FOOTBALL A-D, SQUASH B-C, PRACTICE C-D, TARGET 1 B, TARGET 2 D), RESET and SERVE buttons, and the LEFT PLAYER and RIGHT PLAYER sockets.
  5. ↑ 5.00 5.01 5.02 5.03 5.04 5.05 5.06 5.07 5.08 5.09 5.10 5.11 5.12 5.13 General Instrument Corporation, GIMINI TV Game Circuits, January 1978, pp. 4-7, PDF hosted by Pong-Story (retrieved 2026-10-18). AY-3-8500 data sheet: pin 2 VSS, pin 4 VCC; standard conditions VCC +6 to +7 V; -0.3 to +12 V maximum on any pin; supply current 40 mA typical, 60 mA maximum at +7 V; clock input pin 17, 2.012160 MHz ±1% (1.99 to 2.03 MHz); sound output pin 3 (32 ms tones: 976 Hz hit, 488 Hz boundary, 1.95 kHz score); ball angles pin 5, ball speed pin 7 (open 1.3 s, grounded 0.65 s to cross the screen), manual serve pin 8 (grounded for automatic serving; when open the game stops after each score and a serve is made by momentarily grounding the pin), bat size pin 13, game select pins 18 to 23 (rifle 1, rifle 2, tennis, soccer, squash, practice), each grounded to select; reset pin 25, momentarily grounded; shot and hit inputs pins 26 and 27, positive pulses from monostables in the rifle circuit; sync output pin 16; bat inputs pins 11 and 12 fed by R-C networks, "Use a 10K resistor in series with each pot"; control inputs have on-chip pull-ups and need a contact resistance of no more than 1 kΩ to VSS; reference circuits with 1 MΩ bat potentiometers and 0.1 µF bat capacitors.
  6. ↑ 6.0 6.1 Photograph by José Antonio Ortigueira Amor, File:Adman Grandstand 3600 MK II Colour (15).jpg (CC BY 4.0, from Wikimedia Commons), examined at full size: the base, with the label "COLOR TV-GAME / PATENTS BRITISH NO: 1268821 AND 1328223 AND IN OTHER 18 COUNTRIES / BATTERY: UM-2 x 6 OR AC ADAPTOR (9V / 100 MA) / SERIAL NO: 070957 / MADE IN HONG KONG", a moulded "EXTERNAL POWER" marking with an arrow at one side, a pattern of holes over the speaker, a battery cover with two tabs, two rubber feet at one end with a case screw in a recess beside each, and two moulded feet at the other end.
  7. ↑ 7.0 7.1 7.2 7.3 7.4 General Instrument Corporation, GIMINI TV Game Circuits, January 1978, pp. 73-83: Astec International application notes on PAL colour for the AY-3-8500, PDF hosted by Pong-Story (retrieved 2026-10-18). The 2.0 MHz game clock must be at exactly the right frequency, because on PAL receivers with a delay line a wrong clock makes picture detail appear doubled; the 4.433618 MHz subcarrier oscillator needs careful alignment and stability. "An alternate colour encoding system" uses only two CMOS packages, a 4069 hex inverter and a 4075 triple 3-input OR gate, with one transistor, ahead of an Astec colour encoder and modulator; its subcarrier "should be aligned to 4.433619MHz with a maximum tolerance of ±50Hz", because the pull-in range of the average colour television is only about 400 Hz; standard modulators are tuned to channel E3 (VHF) or E36 (UHF).
  8. ↑ Photograph by José Antonio Ortigueira Amor, File:Adman Grandstand 3600 MK II Colour (6).jpg (CC BY 4.0, from Wikimedia Commons): the left side of the case, with a single socket, beside the LEFT PLAYER end of the panel.
  9. ↑ 9.0 9.1 David Winter, Pong-Story, "PONG in a Chip" (retrieved 2026-10-18): the AY-3-8500 plays four ball-and-paddle games and two target-shooting games, with settings changed by switches (professional: fast ball, small players, 20° angle; amateur: slow ball, long players, 20° and 40°); a seventh undocumented game, Handicap, in which the right-hand player has a third paddle, is played when none of the six is selected; the chip was used in "hundreds of different game systems".
  10. ↑ Photograph by José Antonio Ortigueira Amor, File:Adman Grandstand 3600 MK II Colour (2).jpg (CC BY 4.0, from Wikimedia Commons), examined at full size: the console with its box ("ADMAN GRANDSTAND TV GAME 3600 MK II", "COLOUR"), the two grey cylindrical hand controllers on grey leads ending in jack plugs, and the light gun marked "THUNDERCOLT Super Marksman 304", whose lead ends in a twin plug with two jack pins of different sizes.
  11. ↑ South-West Retro Computing Archive (University of Plymouth), "Adman Grandstand TVG-3600 MKII" (retrieved 2026-10-18): photographs of a second, boxed TVG-3600 Mk II with its hand controllers, the two sockets in the side of the case, and a base label with the same wording as the Commons console's, serial number 40213.
  12. ↑ Centre for Computing History, "Adman Grandstand 3600 Mk II TV Game", CH39823 (retrieved 2026-10-18): "A four-game, colour, Pong console from Adman Grandstand. Supplied with light gun."; dated 1977.
  13. ↑ Photograph by José Antonio Ortigueira Amor, File:Adman Grandstand 3600 MK II Colour (13).jpg (CC BY 4.0, from Wikimedia Commons; larger copy on the owner's blog), examined at full size: the upper case seen from below with the base removed; the solder side of the board, held by two screws; the RF lead held to the case by a plastic clip and screw; a round opening in the board where the speaker sits; coloured flying leads soldered to the board.


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