Grandstand TV Games Troubleshooting Guide
.jpg)
Symptom-by-symptom fault-finding for the Grandstand pong-type TV games: the TV Game 2000, TV Game 3000, TV Game 2600 Mk II, TV Game 3600 Mk II, TV Game 3600 Mk III, Model 4600, Model 5000 and Model 6000. No service manual or schematic has been found for any Grandstand TV game, and no repair thread about a Grandstand TV game in particular has turned up. The tests below therefore rest on General Instrument's published data for the AY-3-8500 game chip, on photographs of opened consoles, and on the notes of the collector who photographed them, one of whose consoles has a failed capacitor.[1][2] Opening the consoles, power, the RF output and controller care are covered on Grandstand TV Games General Maintenance.
Before you start
[edit | edit source]- You need a multimeter, a television or monitor with an analogue UHF tuner, and ideally a regulated bench supply with a current limit. Set it to 9 V and a limit of about 150 mA. The 3600 Mk II and 4600 labels rate the consoles at 100 mA, and the 2000's base gives 360 mW at 9 V, which is 40 mA.[3][4][5]
- Find out the polarity of the console's power socket before connecting anything: it differs between models. The owner of the photographed consoles gives the 2000 as centre negative and the 3600 Mk II and 4600 as centre positive.[2][6][7]
- The capacitors are now close to 50 years old. The TV Game 2000 in the photographs had one explode inside the case.[2] Wear eye protection the first time you power a console that has not been recapped, and keep your face away from the open board.
- The consoles run from 9 V. The only mains hazard is an original mains adaptor: a cracked case or perished lead can expose mains voltage.
Power faults
[edit | edit source]| Symptom | Probable cause | Action |
|---|---|---|
| Dead on batteries and on the adaptor | Flat or corroded cells; corroded springs; a lead from the battery compartment broken by corrosion; a faulty power switch; a failed part in the supply section | Measure the battery pack with the cells fitted: six fresh C cells give about 9 V. Check continuity from the battery terminals to the board, then through the power switch. Inspect the electrolytic capacitors and resistors near where the supply enters the board. |
| Works on batteries, not on the adaptor | Adaptor of the wrong polarity or voltage; dirty or loose power socket | Measure the adaptor's voltage and polarity and compare them with the console's socket. Clean the socket contacts. |
| Works on the adaptor, not on batteries | Corroded battery springs; broken battery lead; a switching contact in the power socket that no longer reconnects the batteries when the plug is out (if the socket has one) | Clean the springs (see Battery Explosion, Capacitor or Corrosion Damage). Check continuity from the battery terminals to the board with the plug removed. |
| A crack, a smell of hot electrolyte or smoke at switch-on | A failed electrolytic capacitor; a supply connected the wrong way round | Switch off at once. Open the console and look for burst or bulging capacitors and darkened resistors. See Grandstand TV Games Capacitor Replacement Guide. |
| Current well above the label rating, or the supply's current limit trips | A shorted capacitor or another short on the board | The AY-3-8500 itself draws 40 mA typical and 60 mA at most.[1] Feel for a part that warms up, then check the capacitors across the supply first. |
Picture faults
[edit | edit source]| Symptom | Probable cause | Action |
|---|---|---|
| Only noise on the television, with no change when the console is switched on | The set is not tuned to the console's channel, or has no analogue tuner; broken RF lead or plug; no supply to the modulator | Tune by hand around the console's channel (UHF 30 for the 2000, UHF 36 for the 4600).[2][5] Check the lead and plug. Measure the supply at the modulator's power connection. |
| A steady blank or grey screen, but no playfield or scores | The modulator works but the game chip is not running: no supply or no clock | Measure the chip's supply (pin 4 to pin 2 on an AY-3-8500: GI's operating range is +6 to +7 V). Check the clock on pin 17 with an oscilloscope or frequency counter.[1] |
| Picture rolls, tears or breaks into diagonal bands | Television fine tuning; clock off frequency; on the 2000, the HORI-HOLD adjustment | Fine-tune the television first. On the 2000, turn HORI-HOLD slowly through its range.[2] On an AY-3-8500 console the clock should be 2.012160 MHz ±1%.[1] |
| A 3600 Mk II or 4600 gives a black and white picture | Television colour setting or fine tuning; colour subcarrier off frequency; a fault in the colour circuit | Fine-tune the set and check its colour control. GI's PAL application note asks for the game's subcarrier to be within ±50 Hz of 4.433619 MHz, because an average colour television only locks within about 400 Hz.[8] Measure the subcarrier with a frequency counter before turning the trimmer beside the 3600 Mk II's 4.433618 MHz crystal.[4] On the 4600, look at the area around the TBA520.[5] |
| Playfield and scores, but one bat missing | Open-circuit potentiometer; broken controller lead; dirty or broken controller jack (3600 Mk II) | Measure the potentiometer through its lead. On the 3600 Mk II swap the two controllers between the jacks to tell a controller fault from a console fault.[6] |
| A bat jumps or jitters | Dirty or worn potentiometer track | Clean the potentiometer, as described on the maintenance guide. |
| A bat stays at the top or bottom of the screen | Potentiometer or its wiring open or shorted; a fault in the bat's R-C network | On an AY-3-8500 the bat inputs are pins 11 and 12; GI's reference circuit puts a 10 kΩ resistor in series with each potentiometer and a capacitor on each input.[1] Check those parts. |
Game, controls and sound
[edit | edit source]| Symptom | Probable cause | Action |
|---|---|---|
| The game stops after each point | Manual serve selected | This is normal. With manual serve the AY-3-8500 waits after each score until SERVE is pressed.[1] Press SERVE, or set the serve switch to AUTO. |
| A game that is not on the selector appears (football with a third bat on the right), or the selector gives the wrong game | A game-select contact is not closing. With none of its six games selected, the AY-3-8500 plays a seventh, undocumented game called Handicap.[9] | Clean the game-select switch and work it end to end. |
| Target games missing on a 3600 Mk II | Light gun not plugged in | On the photographed 3600 Mk II the two target games appear only when the gun is connected.[6] |
| Scores will not reset | RESET contact dirty or open | The AY-3-8500 resets when pin 25 is briefly connected to ground.[1] Clean the button and check its wiring. |
| Bat size, ball speed or rebound angle does not change | Dirty slide switch | Each of these settings is a switch to ground on the chip (pins 13, 7 and 5 on an AY-3-8500).[1] Clean the switch. |
| No sound | Broken speaker lead; open-circuit speaker; failed driver transistor | Measure the speaker; it should read close to its marked impedance (the 3600 Mk II's speaker is marked 8 Ω).[4] The AY-3-8500's sound output is pin 3; GI's reference circuit drives the speaker through a transistor.[1] |
| Sound works but there is no picture | The chip is running; the fault is between the chip's video outputs and the RF lead | Check the modulator's supply and the RF lead. |
Light gun faults
[edit | edit source]- Test the gun on a cathode-ray tube television. Light guns of this period detect the CRT's scanning beam and do not work with flat-panel sets.
- On an AY-3-8500, the gun circuit sends a pulse to pin 26 when the trigger is pulled and to pin 27 when the target is in the sights.[1] If the gun never scores, check the trigger switch, the lens, the lead and both plugs, and then those two pins.
- On the 3600 Mk II the gun has two plugs: a jack and a mini-jack on the right side of the case. Both must be in.[6]
Component-level tests
[edit | edit source]AY-3-8500 pin reference
[edit | edit source]These pin numbers apply to the 3600 Mk II and the 4600, which have the AY-3-8500.[4][5]
| Pin | Function | What to check |
|---|---|---|
| 2 | VSS (ground) | Reference for all measurements |
| 4 | VCC (positive supply) | +6 to +7 V in operation; never above +12 V |
| 17 | Clock input | 2.012160 MHz ±1% |
| 16 | Sync output | Pulses when running |
| 3 | Sound output | Tone bursts on hits and scores |
| 6, 9, 10, 24 | Ball, right player, left player, score and field video outputs | Pulses when running |
| 11, 12 | Right and left bat inputs | A rising edge whose timing each potentiometer sets |
| 18-23 | Game select: Rifle 1, Rifle 2, Tennis, Soccer, Squash, Practice | One pin pulled to ground by the selector |
| 5, 7, 8, 13 | Ball angles, ball speed, manual serve, bat size | Ground or open according to the switches |
| 25 | Reset | Grounded only while RESET is pressed |
| 26, 27 | Shot and hit inputs (light gun) | Pulses from the gun circuit |
| 1, 14, 15, 28 | Not connected | GI says not to use them as tie points |
Source: General Instrument's 1978 catalogue.[1]
Supply and clock checks
[edit | edit source]| Point | Expected | Source |
|---|---|---|
| Battery or adaptor input | 9 V | Base labels[3][4][5] |
| AY-3-8500 pin 4 to pin 2 | +6 to +7 V (GI's standard operating condition) | [1] |
| AY-3-8500 clock, pin 17 | 2.012160 MHz ±1% | [1] |
| PAL colour subcarrier (3600 Mk II) | 4.433619 MHz ±50 Hz (GI application note) | [8] |
| Supply current | 40 mA typical, 60 mA maximum for the AY-3-8500 alone; 100 mA adaptor rating on the 3600 Mk II and 4600 labels | [1][4][5] |
The TMS1965 in the TV Game 2000
[edit | edit source]No Texas Instruments data sheet for the TMS1965 has been found. Pong-Story and the HomeComputerMuseum both describe it as pin-compatible with the AY-3-8500.[9][10] If that holds, the AY-3-8500 table above applies, but confirm the supply and ground pins by tracing them on the 2000's board before relying on it.
What can be repaired
[edit | edit source]| Part | Repairable? | Notes |
|---|---|---|
| Electrolytic capacitors, resistors, diodes, small transistors | Yes | Standard through-hole parts. Read the value from the old part before removing it; no parts list exists. See Grandstand TV Games Capacitor Replacement Guide. |
| Slide switches, push buttons, potentiometers, jacks, leads | Yes | Clean first. Replace a potentiometer with one of the value measured on the original. |
| Crystals | Yes | The 3600 Mk II uses 2.000000 MHz and 4.433618 MHz crystals, both ordinary values.[4] |
| RF modulator | Partly | The 2000's modulator is a sealed KDC module;[3] the 3600 Mk II and 4600 build theirs on the board under a screen.[4][5] No replacement module or modification has been documented for these consoles. |
| Game chip | Only by transplant | The AY-3-8500 and TMS1965 have long been out of production. The AY-3-8500 was used in hundreds of different consoles,[9] so the realistic source is another console or old stock. Rule out the supply, the clock and the switches before blaming the chip. |
| Case, labels, controller shells | Yes | Clean as described on Grandstand TV Games General Maintenance. |
Model notes
[edit | edit source]TV Game 2000
[edit | edit source]- Texas Instruments TMS1965NL with an RCA CD4071BE; board marked GAMATIC-7600.[3]
- The unit in the photographs does not work. One of the capacitors near the left edge of the board exploded, scattered its contents inside the case and knocked a resistor off its solder pads.[2] The failed capacitor is a SAMHWA 470 µF 16 V electrolytic.[3] If yours is dead, look first for a burst or bulging electrolytic and for loose or darkened parts beside it. Details are on Grandstand TV Games Capacitor Replacement Guide#TV Game 2000.
- Socket centre negative, unlike the 3600 Mk II and 4600 (owner's notes).[2]
- HORI-HOLD control on the rear for a picture that will not hold steady.[3][2]
TV Game 3000
[edit | edit source]No information on the inside of the 3000 has been found. Use the general tables above, and read the largest chip on the board: if it is an AY-3-8500, the pin reference applies.
TV Game 2600 Mk II
[edit | edit source]A black and white console with a light gun.[11] Nothing is known about its board. Use the general tables and the light-gun section above.
TV Game 3600 Mk II
[edit | edit source]- AY-3-8500, with a 2 MHz clock crystal and a 4.433618 MHz colour crystal.[4]
- Controllers and light gun all plug in, which makes swapping them a quick test.[6]
- The target games appear only with the gun connected.[6]
- For loss of colour, measure the subcarrier before touching the trimmer next to the 4.433618 MHz crystal.[4][8]
TV Game 3600 Mk III
[edit | edit source]A six-game console.[12] Nothing is known about its board. Use the general tables above.
Model 4600
[edit | edit source]- AY-3-8500 and TBA520.[5]
- The photographed board has brown deposits and corrosion on and around several parts. On a console with intermittent faults, clean the board and check the tracks and joints under the deposits before replacing anything.[5]
- Socket centre positive (owner's notes; it worked on a 9 V centre-positive adaptor).[7]
Model 5000
[edit | edit source]A ten-game colour console with motorcycle games and two light guns.[13] Nothing is known about its board. Use the general tables and the light-gun section above.
Model 6000
[edit | edit source]A ten-game colour console with joysticks.[14] Nothing is known about its board. A bat that drifts or jumps in one direction only points to the joystick control for that axis.
Related pages
[edit | edit source]- Grandstand TV Games General Maintenance
- Grandstand TV Games Capacitor Replacement Guide
- Grandstand Universal Mains Adaptor
- Capacitor Failure Symptoms
- Battery Explosion, Capacitor or Corrosion Damage
References
[edit | edit source]- ↑ 1.00 1.01 1.02 1.03 1.04 1.05 1.06 1.07 1.08 1.09 1.10 1.11 1.12 1.13 General Instrument Corporation, GIMINI TV Game Circuits, January 1978, pp. 4-7, PDF hosted by Pong-Story (retrieved 2026-10-18). AY-3-8500 and AY-3-8500-1 data: 625-line and 525-line versions; "intended to be battery powered"; 28-pin pin-out (pin 2 VSS, pin 4 VCC, pin 3 sound output, pin 16 sync output, pin 17 clock input, pin 24 score and field output); pin functions; standard conditions VCC +6 to +7 V; power supply current 40 mA typical and 60 mA maximum at VCC +7 V; -0.3 to +12 V maximum on any pin; clock 2.012160 MHz ±1%; each bat input fed by an R-C network, "Use a 10K resistor in series with each pot"; reference circuit with 1 MΩ bat potentiometers, 0.1 µF bat capacitors and a 10 µF supply capacitor.
- ↑ 2.0 2.1 2.2 2.3 2.4 2.5 2.6 2.7 José Antonio Ortigueira Amor, "Consola pong Adman Grandstand TV Game 2000 (WK-I HB) (1977)", Retro Ordenadores Orty (collector's blog, in Spanish), 7 November 2023 (retrieved 2026-10-18). First-hand description of the photographed TV Game 2000: TMS1965NL and CD4071BE on the board; rear socket "AC 9V ADAPTOR" for 9 V DC, centre negative; a "HORI-HOLD" adjustment on the rear; RF lead on UHF channel 30; six 1.5 V LR14 cells in an internal compartment; four screws hold the lower case; board marked GAMATIC-7600 and WK-I HB; controllers permanently wired, with SERVE on the left controller and RESET on the right; the console does not work, because a capacitor near the left edge of the board exploded, scattered its contents through the case and knocked a resistor off its solder pads.
- ↑ 3.0 3.1 3.2 3.3 3.4 3.5 Photographs File:Grandstand Adman TV Game 2000 (5).jpg, File:Grandstand Adman TV Game 2000 (6).jpg, File:Grandstand Adman TV Game 2000 (7).jpg and File:Grandstand Adman TV Game 2000 (8).jpg (José Antonio Ortigueira Amor, CC BY 4.0, from Wikimedia Commons), examined at full resolution. They show the solder side (silkscreen GAMATIC-7600 and WK-I HB), the canned RF modulator labelled "KDC UM-1111E 30", the component side with a Texas Instruments TMS1965NL (date code KA 7740) and an RCA CD4071BE, the failed SAMHWA 470 µF 16 V capacitor and a resistor beside it, and the base label (9 V DC from six UM-2 cells or a 9 V adaptor; 360 mW; made in Korea).
- ↑ 4.00 4.01 4.02 4.03 4.04 4.05 4.06 4.07 4.08 4.09 Photographs File:Adman Grandstand 3600 MK II Colour (13).jpg, File:Adman Grandstand 3600 MK II Colour (14).jpg and File:Adman Grandstand 3600 MK II Colour (15).jpg (José Antonio Ortigueira Amor, CC BY 4.0, from Wikimedia Commons), examined at full resolution. Component side: General Instrument AY-3-8500 (7831, Taiwan), Motorola MC14075B, RCA CD4069UBE, crystals marked "2.000000 K.D.S" and "4.433618 K.D.S", a green trimmer beside the 4.433618 MHz crystal, a screened modulator section, adjustable coils in metal cans, a TOA speaker, seven slide switches and two jacks. Base label: COLOR TV-GAME; UM-2 × 6 or AC adaptor 9 V / 100 mA; made in Hong Kong.
- ↑ 5.0 5.1 5.2 5.3 5.4 5.5 5.6 5.7 5.8 Photographs File:Grandstand 4600 colour - PCB.jpg, File:Grandstand 4600 colour - Internals.jpg, File:Grandstand 4600 colour - Back.jpg and File:Grandstand 4600 colour - With detached controllers.jpg (José Antonio Ortigueira Amor, CC BY 4.0, from Wikimedia Commons), examined at full resolution. Component side: General Instrument AY-3-8500 (8138 SFA), TBA520 (F8133, Indonesia), two National CD4069CN / MM74C04N, a transistor marked 9015, a screened modulator, a long game-select slide switch, six slide switches SW1 to SW6, a yellow trimmer, electrolytics at C37, C38 and C39, and brown deposits and corrosion around several parts. Solder side silkscreen: REV.2 11-00161-00. Base label: UHF CHANNEL 36; 6 × UM-2 batteries or AC adaptor 9 V DC 100 mA; made in Hong Kong. The uploader's description names the AY-3-8500 and calls the TBA520 a PAL chroma demodulator.
- ↑ 6.0 6.1 6.2 6.3 6.4 6.5 José Antonio Ortigueira Amor, "Consola pong Adman Grandstand TV Game 3600 MK II Colour (1978)", Retro Ordenadores Orty (collector's blog, in Spanish), November 2023 (retrieved 2026-10-18). First-hand description of the photographed 3600 Mk II: AY-3-8500, MC14075B and CD4069UBE on the board; two separate controllers that plug into LEFT PLAYER and RIGHT PLAYER jacks; 9 V DC centre-positive socket on the left side; a jack and a mini-jack for the light gun on the right side; the two target games appear only when the light gun is plugged in; six LR14 cells; four screws hold the lower case and two hold the board to the upper case; the console works, in colour.
- ↑ 7.0 7.1 José Antonio Ortigueira Amor, "Consola Grandstand 4600 Colour Video Sports Centre (1977)", Retro Ordenadores Orty (collector's blog, in Spanish), December 2021 (retrieved 2026-10-18). First-hand description of the photographed 4600: AY-3-8500 and TBA520 on the board; controllers press into bays in the case but stay wired to the console; on the Deluxe version the RESET button is on the controllers; rear socket for 9 V DC, centre positive; RF lead (PAL, channel 36); six LR14 cells; four screws hold the lower case, two of them inside the battery compartment; five screws hold the board to the upper case; tested on a 9 V DC centre-positive adaptor and working.
- ↑ 8.0 8.1 8.2 General Instrument Corporation, GIMINI TV Game Circuits, January 1978, pp. 76-83: Astec International, "PAL Colour Encoding Systems for the AY-3-8500 TV Game Circuit". The "alternate colour encoding system" uses two CMOS packages, a 4069 hex inverter and a 4075 triple three-input OR gate, one transistor and a standard TV 4.43 MHz crystal (Fig. 10 shows a +6.5 V rail). The subcarrier oscillator "should be aligned to 4.433619 MHz with a maximum tolerance of ±50 Hz", because the pull-in range of an average colour television is only about 400 Hz; a crystal oscillator is recommended for the 2.000 MHz system clock; standard RF modulators are tuned to channel E3 (VHF) or E36 (UHF). PDF hosted by Pong-Story.
- ↑ 9.0 9.1 9.2 Pong-Story, "PONG in a Chip" (retrieved 2026-10-18). History of the single-chip ball-and-paddle circuits: Texas Instruments' TMS-1955 and TMS-1965 (1976) were "both pin compatible with the General Instruments AY-3-8500"; the AY-3-8500 plays four ball-and-paddle games and two target-shooting games, plus a seventh undocumented game, Handicap, when none of the six is selected; it was used in "hundreds of different game systems"; GI chips with a -1 suffix are the 525-line (NTSC) versions; GI chip list including the AY-3-8603 (Roadrace), AY-3-8605 (Submarine), AY-3-8606 (Wipe-Off), AY-3-8607 (target shooting), AY-3-8610, AY-3-8700/8710 (tank battle) and AY-3-8760/8765 (motor cycle).
- ↑ HomeComputerMuseum (Helmond, Netherlands), "Gamatic 7600" (retrieved 2026-10-18). Museum catalogue entry: the Gamatic 7600 was sold under many brands, "as the Grandstand T.V. Game Model 2000 for example"; made in Korea; board labelled "F'GAMATIC-7600"; four games from the Texas Instruments TMS-1965, which it calls "pin-to-pin compatible" with the AY-3-8500; six cells or an external 9 V DC supply, 360 mW.
- ↑ Centre for Computing History, "Adman Grandstand TVG-2600 Mk II", object CH22783 (retrieved 2026-10-18). Museum record: Pong-style console from 1977; Tennis, Football, Squash and Target Shooting with the supplied light gun, a "Thundercolt Super Marksman 304"; two handheld controls; serial number 93097.
- ↑ Centre for Computing History, "Adman Grandstand 3600 Mk III TV Game", object CH50705 (retrieved 2026-10-18). Museum record: "A six-game Pong console from Adman Grandstand", dated 1977.
- ↑ Centre for Computing History, "Adman Grandstand TV Game Model 5000", object CH32311 (retrieved 2026-10-18). Museum record, 1977: box text "Colour video sports centre with remote control handsets - 10 exciting fun games with electronic console control"; two light-gun accessories with detachable stocks and rifle barrels; games Motor Cross, Enduro, Drag Race, Stunt Cycle, Practice, Squash, Soccer, Tennis, Rifle no 1 and Rifle no 2.
- ↑ Centre for Computing History, "Grandstand 6000 Colour", object CH31304 (retrieved 2026-10-18). Museum record, 1978: Colour Video Sports Centre with ten games (Basketball Practice, Practice, Tennis, Basketball, Squash, Hockey, Football, Gridball, Rifle No. 1 and Rifle No. 2); "This console used joysticks rather than the rotary paddles which meant the bats could move in two dimensions."
.jpg){kind=link}
.jpg){kind=link}
.jpg){kind=link}
.jpg){kind=link}
.jpg){kind=link}
.jpg){kind=link}
