Grandstand Match of the Day 2000 General Maintenance

The Grandstand Match of the Day 2000 is a compact four-game black-and-white Pong console made in Hong Kong for Adam Imports, with a large central speaker and two small controller pods that rest in recesses at the front. No manual, service information or inside photograph has been published. A collector's photographs of a complete example show the panel, the base with its screws and battery compartment, the controllers and the rear, and General Instrument's data for the AY-3-8500, whose four bat-and-ball games and options the console matches, gives the electrical limits for the switches. Nothing has been published on the chip actually fitted, the supply voltage or the inside.

Fault-finding is on Grandstand Match of the Day 2000 Troubleshooting Guide; the electrolytic capacitors are covered on Grandstand Match of the Day 2000 Capacitor Replacement Guide.

At a glance

Match of the Day 2000: published facts

Part	Detail	Source
Panel	Brushed silver; four-position red game slider (TENNIS, HOCKEY, SQUASH, PRACTICE); switches POWER, BAT SIZE, SPEED, ANGLE, SERVE; red START and MAN. buttons; large round speaker grille
Controllers	Two flat black pods with red knobs, resting in recesses at the front
Base	Battery compartment with ribbed cover; a screw in a recess at each front corner; stickers "INSPECTED PASS U", "CHANNEL 36 ±5", "Made in Hong Kong"
Rear	RF lead with a Belling-Lee plug; small jack socket for an external supply
Picture	Black and white, 625-line UHF
Game chip, supply voltage, polarity, cell type	Not published	None found

Before you start

• Open the battery cover and look for any marking of the cell size, number and polarity moulded in the compartment. No source gives them.
• The rear socket takes an external supply, but no voltage or polarity has been published. Do not connect an adaptor until you have measured the socket against the battery contacts.
• Remove the cells and lift both controller pods out of their recesses before turning the console over.
• You will need a cross-head screwdriver, a multimeter, contact cleaner suitable for switches and potentiometers, isopropyl alcohol, a soft brush and a camera.

Opening the case

No account of opening a Match of the Day 2000 has been published. The base photographs show what to look for:

1. Take out the cells and look inside the battery compartment for screws.
2. Remove the two screws in the recesses beside the feet at the front corners of the base.
3. Look into the two square openings at the rear corners before lifting anything. The photographs do not show what is inside them; they may hold further screws or catches.
4. Lift the base away slowly. The pods' leads, the RF lead and the large speaker behind the panel grille all have to connect to the board somewhere inside, so do not pull on any lead.
5. Before any lead is unplugged or desoldered, photograph it, and photograph the board from both sides.

Record what you find, because none of it has been published: the game chip's markings, the crystal, the RF modulator and any channel marking, the board's printed number, the regulator, and each electrolytic capacitor's value and voltage.

Cleaning

• Clean the black plastic with a cloth barely damp with soapy water. Keep cleaner off the brushed silver panel: its legends, the game pictograms and the "Match of the Day 2000" name are printed on.
• Brush the dust out of the round speaker grille. Do not wash it: the speaker sits directly behind it.
• Brush out the two recesses that hold the controller pods.
• Clean the board, once open, with isopropyl alcohol and a soft brush.

Game slider, switches and buttons

If the Match of the Day 2000 uses the AY-3-8500, which is not confirmed, its controls go to these pins: TENNIS, SOCCER (the panel's HOCKEY), SQUASH and PRACTICE to pins 20 to 23, BAT SIZE to 13, SPEED to 7, ANGLE to 5, SERVE to 8 and START to the reset input on 25.

The games are chosen with a red four-position slider at the left of the panel: TENNIS, HOCKEY, SQUASH and PRACTICE. On the right are five slide switches, POWER (ON, OFF), BAT SIZE (S, L), SPEED (H, L), ANGLE (20°/40° or 20°) and SERVE (MAN., AUT.), with a red START button below the slider and a red MAN. button beside the SERVE switch.

If the chip is General Instrument's AY-3-8500, as the games and options suggest, every game and setting is chosen by connecting one of its inputs to ground, and GI allows no more than 1 kΩ through a closed contact. MAN. would be the manual serve and START the reset input that clears the scores and starts a new game.

• Put a short burst of switch cleaner into each of the five slide switches and slide it back and forth ten or twelve times.
• Work the game slider through its four positions and check that it seats in each. A slider resting between positions leaves no game selected, and the AY-3-8500 then plays a hidden football variant with a third bat on the right.
• Clean the START and MAN. contacts.

Controller pods

The two pods are flat black boxes with a red knurled knob, and each rests in a recess at the front of the console. The underside of each pod is a closed box held by one central screw, with the lead entering at one end.

• To reach the potentiometer, remove the central screw on the underside of the pod. Note how the lead is anchored before separating the parts.
• A bat that jumps or sticks usually means a dirty potentiometer track. Spray potentiometer cleaner into the track and turn the knob end to end. GI's reference circuit uses 1 MΩ bat potentiometers; the values in these pods have not been published.
• Lift a pod out of its recess by the pod, not the lead, and check each lead where it enters the pod and the case.
• No controller sockets appear in the photographs, so the leads are probably wired to the board inside and the pods cannot be swapped between sides to test them. Check a suspect pod's potentiometer with a meter instead: the resistance should change smoothly as the knob turns.

Speaker

The speaker is large and sits behind the round grille that takes up the centre of the panel. There is no sound switch on the panel.

• Check the cone for tears and the leads for breaks if the console is silent.
• On the AY-3-8500 the sound comes from pin 3 through a driver transistor; GI's reference circuit drives an 8 Ω speaker through a 2N2222.

Power

• The box promises "battery or AC operation". The battery compartment in the base has coil-spring contacts at both ends under a ribbed cover with a tab.
• The external supply goes into a small jack socket at the rear, at the opposite end from the RF lead. Measure its polarity against the battery contacts before connecting anything.
• Grandstand's own Grandstand Universal Mains Adaptor was sold for the handhelds and tabletops and has a polarity switch; the tabletop leaflets tell owners to set it to negative. Do not assume that setting suits this console: measure first.
• Mains voltage is present only inside an original plug-in adaptor; inspect its case and flex for cracks or exposed conductors before plugging it in.
• Take the cells out before storing the console. If old cells have leaked, Battery Explosion, Capacitor or Corrosion Damage covers the clean-up.

RF output

• The RF lead is fixed and ends in a standard Belling-Lee aerial plug.
• A sticker on the base reads "CHANNEL 36 ±5". Tune an analogue UHF television around channel 36; GI's application notes give UHF channel E36 as 591.25 MHz. A television with only a digital tuner will not show the picture.
• The box says the console plays in black and white on 625-line UHF televisions.

Wearing parts

What wears on a Match of the Day 2000

Part	Check
Game slider and five slide switches	Clean and work each one; check the slider seats in all four positions
START and MAN. buttons	Clean the contacts
Controller pods and their leads	Clean the potentiometers; check the leads at both ends
Speaker	Cone and leads
RF lead and Belling-Lee plug	Check the plug and the lead where it leaves the case
Electrolytic capacitors	Not documented; see Grandstand Match of the Day 2000 Capacitor Replacement Guide
Battery springs	Remove cells for storage

Storage

• Remove the cells.
• Rest the pods in their recesses with the leads loosely folded, not wound tight.
• Keep the console, and its box if you have one, dry and flat.

Preventive maintenance checklist

1. Read any marking in the battery compartment, then measure the rear socket's polarity against the battery contacts.
2. Clean the four-position slider, the five slide switches and the two buttons.
3. Open each pod with its central screw and clean the potentiometer.
4. Check the speaker, the pod leads and the RF lead.
5. Tune an analogue UHF television near channel 36 and try all four games at both speeds.
6. If you open the case, photograph the board and record the chip, crystal and capacitor values.

Related pages

• Grandstand Match of the Day 2000
• Grandstand Match of the Day 2000 Troubleshooting Guide
• Grandstand Match of the Day 2000 Capacitor Replacement Guide
• Grandstand Universal Mains Adaptor
• Battery Explosion, Capacitor or Corrosion Damage
• Recommended Tools