Grandstand TV Game 2600 Mk III General Maintenance

The base of a colour TVG-3600 Mk II: label, battery cover, speaker holes and a case screw beside each foot at one end. The 3600 Mk III uses the same form of case; no photograph of a 2600 Mk III, inside or out, has been found.

The Grandstand TV Game 2600 Mk III appears in Wikipedia's list of Grandstand consoles as a black-and-white, six-game model made in Hong Kong, and in no other source found. There is no manual, photograph or repair account for it. Its name pairs it with the colour Grandstand TV Game 3600 Mk III, which a collector has photographed in detail; if your console proves to share that model's case and panel, the 3600 Mk III's layout is the best available guide, and its maintenance page covers the procedures in full. Below: how to confirm what you have, then what to look after on a console of that design, with each point marked as coming from the 3600 Mk III.

Fault-finding is on Grandstand TV Game 2600 Mk III Troubleshooting Guide; capacitors are on Grandstand TV Game 2600 Mk III Capacitor Replacement Guide.

Confirm the model

What to compare with the documented 3600 Mk III

Feature	On the 3600 Mk III	Source
Front strip	"ADMAN GRANDSTAND COLOUR TV GAME 3600 MK III"
Game selector	One six-position slider: TENNIS, SQUASH, TARGET-1, SOCCER, PRACTICE, TARGET-2
Other controls	POWER, SERVE (MANUAL/AUTO), SPEED, ANGLE, BAT SIZE (AMATEUR/PROFESSIONAL); orange RESET and SERVE buttons
Sockets	LEFT PLAYER and RIGHT PLAYER on the panel; a pair marked GUN at the right of the panel; external power socket in one side
Base label	"COLOR TV GAME ... BATTERY: UM-2 x 6 OR AC ADAPTOR (9V / 100 MA) ... MADE IN HONG KONG"

Wikipedia lists the 2600 Mk III's target games as skeet and target; note what your panel actually says. A console marked 2600 Mk III that differs from this table is worth photographing in full: no description of one has been published.

Before you start

• Read the base label for the supply. On the 3600 Mk III it is six UM-2 (C) cells or a 9 V 100 mA adaptor; the 2600 Mk III's is unrecorded.
• No label of this family gives the socket's polarity. Measure it against the battery terminals before connecting an adaptor.
• Remove the cells and unplug the controllers and any gun.
• Tools: a cross-head screwdriver, isopropyl alcohol, switch cleaner, potentiometer cleaner, a multimeter and a camera.

Opening the case

On the 3600 Mk III the base carries the battery compartment and the speaker, and two screws sit at the corners of one edge of the base; the cells lie in two rows of three, with two screws in the compartment floor. If your 2600 Mk III has the same base, remove the cells, then the screws, and lift the base carefully: the speaker is fixed to it and its leads run to the board. Photograph the board and every lead before disconnecting anything, and record the chip, crystal and capacitor markings, none of which have been published for either Mk III.

Switches, slider and buttons

• On a single-slider panel, check that the slider seats firmly in each of its six positions. If the chip is an AY-3-8500, a slider resting between positions leaves no game selected and the chip plays a hidden football variant with a third bat.
• Clean each slide switch with switch cleaner and work it a dozen times. The AY-3-8500 reads a setting through a contact to ground and needs 1 kΩ or less when it is closed.
• Clean the RESET and SERVE contacts.

Hand controllers

The 3600 Mk III's controllers are dark brown cylinders with a cream knob, holding only a variable resistor (no serve button), and plug into the panel with mono jack plugs.

• Clean a jumpy potentiometer with potentiometer cleaner, turning the knob end to end.
• Swap the two controllers to tell a controller fault from a socket fault.
• Clean the jack plugs and the LEFT PLAYER and RIGHT PLAYER sockets.

Light gun

The photographed 3600 Mk III came with a black pistol whose barrel extension comes off so that it fits the box, and whose twin plug fits the GUN sockets on the panel. No gun is recorded for the 2600 Mk III.

• Clean the lens, the trigger switch and both pins of the twin plug.
• Test the gun on a cathode-ray tube television; the 3600 Mk III's owner notes that he needs a CRT set to try it.

RF output

The 2600 Mk III is listed as black and white. No channel is recorded. GI's application notes give UHF channel E36 (591.25 MHz) as a standard modulator channel for AY-3-8500 games, so search around it on an analogue UHF television.

Wearing parts

What to check on a 2600 Mk III built like the 3600 Mk III

Part	Check
Game slider and slide switches	Clean; check the slider seats
RESET and SERVE buttons	Clean the contacts
Controllers, jack plugs and panel sockets	Clean; swap to compare
Gun and GUN sockets	Lens, trigger, twin plug
Speaker in the base	Leads intact after opening
Battery springs	Remove cells for storage
Electrolytic capacitors	Not documented; see Grandstand TV Game 2600 Mk III Capacitor Replacement Guide

Preventive maintenance checklist

1. Compare the console with the table above and photograph its labels.
2. Read the supply from the label; measure the socket and any adaptor.
3. Clean the slider, switches and buttons.
4. Clean the controller potentiometers and swap the controllers.
5. Try every game, the target games with the gun on a CRT set.
6. Store with the cells removed.

Related pages

• Grandstand TV Game 2600 Mk III
• Grandstand TV Game 2600 Mk III Troubleshooting Guide
• Grandstand TV Game 2600 Mk III Capacitor Replacement Guide
• Grandstand TV Game 3600 Mk III General Maintenance
• Grandstand Universal Mains Adaptor
• Battery Explosion, Capacitor or Corrosion Damage