Coleco Telstar Colortron Troubleshooting Guide
Fault-finding for the Coleco Telstar Colortron (model 6135), Coleco's 1978 colour Pong console built on General Instrument's AY-3-8510.[1] Coleco's trouble-shooting sheet for the Colortron survives and is reproduced below.[2] No schematic, board photograph or data sheet for the AY-3-8510 has been found, and no repair report for this model, so the checks beyond Coleco's chart are limited to the supply, the controls and the RF connection. Cleaning is on Coleco Telstar Colortron General Maintenance.
What should happen at power-on
[edit | edit source]With two fresh 9 V alkaline batteries or a Coleco 2099 or 6041 adapter, the switch box set to GAME and a colour television tuned to the channel set on the back of the console:[3][4]
- Moving the slide switch from OFF to INTERMEDIATE or PRO turns the game on. Any one of the four games may appear, and it may differ from one power-up to the next.[5]
- If only the scores appear, with no ball, paddles or boundaries, pressing RESET starts the game.[5]
- Each press of GAME SELECT steps to the next game; RESET starts a new game.[5]
- The field and ball are white on a green background, with the paddles and scores in red and black.[6]
- Hit, score and rebound sounds come from a piezo beeper in the console.[3][1]
Coleco published no voltages for the Colortron. Each battery should read about 9 V, and the Model 6041 adapter is rated 9 V DC at 200 mA.[3][7] General Instrument's figures for the AY-3-8500 do not apply to the AY-3-8510, whose pin-out has not been published.[8]
Coleco's trouble-shooting chart
[edit | edit source]Coleco asks the owner to check the television and switch box connections and, on battery power, to replace the batteries before anything else.[2]
| Symptom | Coleco's remedy | Bench follow-up |
|---|---|---|
| No game; faint TV picture or herringbone pattern | Replace or refit the batteries; set the switch box to GAME and plug the cable in properly; attach the antenna lead as instructed; plug the adapter in (Telstar adapter only); switch on; tune to channel 3, or 4 if the game is set to 4; adjust fine tune[2] | Measure each battery under load and at its snap clip; check that the channel switch on the back is fully in one position[4] |
| Stripes; lots of dots | Adjust horizontal hold; reduce colour intensity; adjust fine tune and contrast[2] | Try a second television before suspecting the console |
| Picture rolls or flutters; bottom line off screen; buzzing from the TV | Adjust vertical hold; turn the TV volume down[2] | As above |
| Vertical or horizontal line moving across the screen | Press RESET; adjust contrast[2] | None needed if RESET clears it |
| No ball; ball or paddles erratic; one or both paddles missing; score not 0-0 | Replace or refit the batteries; switch off and let the game cool, and do not stand it on the television; press RESET rapidly[2] | Weak batteries are the usual cause; clean the snap clips and the slide switch |
Faults beyond Coleco's chart
[edit | edit source]| Symptom | Likely cause | Action |
|---|---|---|
| Picture but no sound, or sound but no picture | One of the two batteries flat or disconnected | Pong-Story reports that one battery runs the games and the other the sound.[1] Test both batteries and both snap clips. |
| Works on the adapter but not on batteries, or the reverse | Snap clip or lead broken; dirty adapter jack; wrong adapter | Inspect the clips and leads. Clean the jack. Coleco warns that any adapter other than its Model 2099 or 6041 may permanently damage the unit, so find out what was used before.[4] |
| Game cuts out when the speed is changed | Dirty slide switch, which carries the power as well as the speed setting | Clean the switch; see Coleco Telstar Colortron General Maintenance#Buttons and the power switch.[4] |
| GAME SELECT does not step to the next game, or skips games | Dirty or worn button contact | Clean or replace the button. The earlier Telstars used slide or rotary game switches, which Pong-Story notes could fail after many selections; the Colortron's push button replaced them.[1][9] |
| One paddle jumps or covers only part of the screen | Dirty or worn control behind the knob; knob slipping on its post | Refit the knob with its flat aligned to the post;[10] clean the control. |
| Colours wrong or missing | Television colour, hue or tint settings; automatic colour control | Adjust colour, hue or tint, and turn automatic colour control off, as Coleco advises.[5] If a set known to be good still shows no colour, the fault is in the console, where the AY-3-8510 produces the colour itself.[8] |
| Picture on neither channel | Channel switch between positions; game cable or switch box | Move the switch firmly to 3 or 4; check the cable and the switch box terminals.[4] |
Things that are not faults
[edit | edit source]- A different game comes on at each power-up.[5]
- Only the scores show after switching on, until RESET is pressed.[5]
- At 15 points the ball passes through the paddles without scoring, then the score bounces and the boundaries disappear.[5]
- In jai alai the ball changes colour after hitting the back wall, to match the paddle of the player who must return it.[5]
- Handball shows two scores: points against on the left, consecutive hits on the right.[5]
- There is no BEGINNER setting: the Colortron has two speeds, INTERMEDIATE and PRO.[3][5]
What is realistically repairable
[edit | edit source]| Part | Repairable? | Notes |
|---|---|---|
| Battery clips, leads and doors | Yes | Standard 9 V snap clips; a printable replacement door exists.[11] |
| Adapter jack | Yes | Clean or replace. |
| GAME SELECT and RESET buttons, slide switch | Usually | Clean first. |
| Paddle controls | Yes | Measure the old part before replacing it. |
| Electrolytic capacitors | Yes | See Coleco Telstar Colortron Capacitor Replacement Guide. |
| AY-3-8510 | Only from another Colortron | Pong-Story knows of no other console that uses it.[8] |
Related pages
[edit | edit source]- Coleco Telstar Colortron
- Coleco Telstar Colortron General Maintenance
- Coleco Telstar Colortron Capacitor Replacement Guide
- Coleco Telstar Colortron Documentation
- Capacitor Failure Symptoms
References
[edit | edit source]- ↑ 1.0 1.1 1.2 1.3 David Winter, Pong-Story, "Coleco Telstar Colortron" (retrieved 2026-10-18): released in 1978; one of the only systems built around GI's AY-3-8510, a derivative of the AY-3-8500; four games in colour; sound from a small piezo beeper; game selection by a push-button rather than a switch; two 9 V batteries, "one for the 'video' (the games), and one for the 'sound'".
- ↑ 2.0 2.1 2.2 2.3 2.4 2.5 2.6 Coleco, Telstar Trouble Shooting Guide, Guide No. 76690, 1978, page 6 of File:Coleco Telstar Colortron Installation Instructions (Guide 76652).pdf: "For units using batteries, replace batteries first before trouble shooting. DO NOT OPEN. THIS DEVICE DOES NOT CONTAIN ANY SERVICEABLE PARTS. Warranty is voided if opened or tampered with."; symptom and remedy chart; accessories No. 2099/6041 AC adapter (battery eliminator) and No. 6111 switch kit, $5.00 each, from Coleco Industries, P.O. Box 460, Amsterdam, N.Y.
- ↑ 3.0 3.1 3.2 3.3 Coleco Industries, Telstar Colortron Installation Instructions and Game Rules, Model No. 6135, Guide No. 76652, 1978, p. 1, File:Coleco Telstar Colortron Installation Instructions (Guide 76652).pdf: four video games (tennis, hockey, jai alai, handball), each in colour; automatic digital display scoring from 0 to 15; realistic audio sounds (hit, score and rebound); two ball speeds; battery operated with two 9 V alkaline batteries, not included; two rubber bumpers pressed and twisted into holes in the bottom ("Do not press too hard so as to damage front of the unit"); foam pads placed in the bottom of the battery compartment; slide out the battery doors and insert two 9 V batteries; avoid leaving batteries in an unused unit; "If your Telstar does not work, replace batteries as your first procedure".
- ↑ 4.0 4.1 4.2 4.3 4.4 Coleco, Guide No. 76652, p. 2: for extended operation a Coleco Model #2099 or #6041 9 volt AC adapter (battery eliminator); "Use of any 9 volt adapter other than Coleco Models #2099 or #6041 may permanently damage your unit"; bottom view with a slide-out door at each end and the battery snapped onto a clip; switch box connections (300 ohm twin lead; a 75 to 300 ohm balun for cable TV); pre-set at the factory for channel 3, with a channel selector switch to move to channel 4 where channel 3 is a strong local station; panel diagram: channel 3 or 4 selector switch and game cable at the rear, AC adapter jack ("use only Coleco AC adapter model"), reset button, left and right paddle controls, game select switch (1 tennis, 2 hockey, 3 jai alai, 4 handball), ON-OFF switch combined with the variable action control (INTERMEDIATE and PRO).
- ↑ 5.00 5.01 5.02 5.03 5.04 5.05 5.06 5.07 5.08 5.09 Coleco, Guide No. 76652, p. 3: turn the power on at Intermediate or Pro; adjust the TV's colour controls, and on some sets the hue or tint control, turning automatic colour control off; Intermediate is the slowest speed and Pro the fastest; after 15 points the ball moves through the paddle without scoring, and after two seconds the score bounces and the boundaries disappear; on black-and-white sets do not turn brightness and contrast to maximum, and shut the Telstar off when not in use; any one of the four games can come on at power-on, and if only the score appears the reset button must be pushed; the GAME SELECT button advances one game per push; game rules, including the jai alai ball changing colour to match the paddle that must hit it next and the two handball scores.
- ↑ Arcade-History, "Telstar Colortron [Model 6135"] (retrieved 2026-10-19): model 6135, 1978; two dials built into the system; General Instruments AY-3-8510; game selection button and reset; colours: green background, white field and ball, red and black for the paddles and scoring; piezo beeper; on-screen score.
- ↑ Photograph by Evan-Amos, File:Coleco-Telstar-AC-Adaptor.jpg (public domain, from Wikimedia Commons): label "TELSTAR AC ADAPTOR MODEL 6041 ... INPUT: 117V 60Hz 5W OUTPUT: 9 V DC 200mA".
- ↑ 8.0 8.1 8.2 David Winter, Pong-Story, "The AY-3-8500 chip: closer view" (retrieved 2026-10-18): the AY-3-8510 is a derivative of the AY-3-8500 in a 16-pin package, with a single pin to select the games, a single video output that is in colour, and no shooting games; released around 1978; the only system known to use it is the Coleco Telstar Colortron.
- ↑ David Winter, Pong-Story, "PONG in a Chip" (retrieved 2026-10-18): on consoles built with GI chips, game selection used a switch "(rotary or linear) which could fail after many game selections".
- ↑ Coleco, Accessory Instruction Sheet for Colortron Model 6135, Guide 76652, page 5 of File:Coleco Telstar Colortron Installation Instructions (Guide 76652).pdf: the decals are aligned against the inside edges of the panels and pressed in place; each control knob goes on its post with the flat surface on the knob aligned with the flat on the post, pressed firmly in place.
- ↑ Robert Trebor, "Coleco Telstar Colortron Battery Door Cover", Thingiverse thing 4710453, 2021, mirrored at the Internet Archive as thingiverse-4710453 (CC BY 4.0; retrieved 2026-10-19): a printable replacement for a missing Colortron battery cover, designed by its owner; "It's a snug fit so you might need a little flat head to get it off".
